Atomic Structure & the Periodic Table Flashcards
What are the main components of an atom?
An atom consists of a central nucleus containing protons and neutrons, surrounded by electrons that orbit in shells.
What is the relative mass and charge of protons?
Protons have a relative mass of 1 and a charge of +1.
What is the relative mass and charge of electrons?
Electrons have a very small relative mass (approximately 1/2000 of a proton) and a charge of -1.
What is the relative mass and charge of neutrons?
Neutrons have a relative mass of 1 and a neutral charge (0).
How does the size of an atom compare to its nucleus?
The nucleus is 10,000 times smaller than the overall size of the atom.
What happens to an atom when it loses electrons?
When an atom loses electrons, it becomes a positive ion.
What happens to an atom when it gains electrons?
When an atom gains electrons, it becomes a negative ion.
What is the atomic number of an element?
The atomic number indicates the number of protons in the atom and defines the element.
How do you calculate the number of neutrons in an atom?
The number of neutrons is calculated by subtracting the atomic number from the mass number.
What does the mass number represent in a nuclide symbol?
The mass number represents the total number of protons and neutrons in the atom.
What is the elemental symbol for oxygen?
The elemental symbol for oxygen is O.
What is the elemental symbol for lithium?
The elemental symbol for lithium is Li.
Why is the number of protons significant in defining an element?
The number of protons determines the identity of the element, as each element has a unique atomic number.
What is the typical radius of an atom?
Atoms typically have a radius of about 0.1 nanometers.
What is the relationship between protons and electrons in a neutral atom?
In a neutral atom, the number of protons equals the number of electrons, balancing the overall charge.
What defines an ion?
An ion is an atom that has gained or lost electrons, resulting in an overall charge.
What is a negative ion?
A negative ion results from an atom gaining electrons, leading to more electrons than protons.
What is a positive ion?
A positive ion results from an atom losing electrons, leading to more protons than electrons.
What does the term ‘empty space’ refer to in the context of an atom?
Most of an atom consists of empty space between the nucleus and the orbiting electrons.
What is the significance of the periodic table in chemistry?
The periodic table organizes different types of atoms (elements) and provides essential information about each one.
What is the structure of an atom?
An atom consists of a central nucleus made up of protons and neutrons, with electrons orbiting around it.
What determines the element of an atom?
The number of protons in the nucleus determines the element of an atom.
What is the atomic number?
The atomic number is the unique number that represents the number of protons in an atom of an element.
How is the periodic table organized?
The periodic table organizes around 100 different elements, with each box representing a different element and its atomic number.
What are isotopes?
Isotopes are different forms of the same element that have the same number of protons but a different number of neutrons.
How does the number of neutrons affect isotopes?
The number of neutrons varies among isotopes, resulting in different mass numbers for the same element.
What is relative atomic mass?
Relative atomic mass is the average mass of all isotopes of an element, taking into account their abundances.
What is the formula for calculating relative atomic mass
Relative atomic mass = (sum of isotope abundance × isotope mass) / (sum of abundances of all isotopes).
What is the abundance of an isotope?
Abundance indicates how common or rare an isotope is compared to other isotopes of the same element.
Calculate relative atomic mass: what is the first step?
Multiply each isotope’s abundance by its mass.
Calculate relative atomic mass: what is the second step?
Sum the results of the products from the first step.
Calculate relative atomic mass: what is the third step?
Divide the sum from the second step by the total abundance of all isotopes.
What is a molecule?
A molecule is a group of two or more atoms held together by chemical bonds.
Can a molecule consist of multiple elements?
Yes, molecules can consist of one element or multiple different elements.
What distinguishes a compound from a molecule?
A compound is a substance that contains two or more different elements, while a molecule can consist of the same or different elements.
Provide an example of a molecule that is not a compound.
Oxygen is a molecule that contains two atoms of the same element and is not a compound.
What is a key feature of compounds regarding their composition?
The elements in a compound are always found in the same proportions.
How is a chemical formula structured?
A chemical formula uses symbols for elements and subscripts to indicate the number of each type of atom.
What do brackets in chemical formulas indicate?
brackets group elements together, with the number outside indicating how many of those groups exist.
What type of bond is present in large compounds like sodium chloride?
Large compounds like sodium chloride are held together by ionic bonds.
How do mixtures differ from compounds?
Mixtures consist of two or more substances that are not chemically combined and can be physically separated.
What methods can be used to separate components of a mixture?
Components of a mixture can be separated using physical methods like filtration, crystallization, or distillation.
Definition of a mixture
A mixture consists of two or more substances that are not chemically combined together.
What is the difference between a mixture and a solution?
A mixture contains a solid that does not dissolve in a liquid (insoluble solid), while a solution contains a solid that dissolves in a liquid (soluble solid).
What is filtration used for in separating substances?
Filtration is used to separate insoluble solids from liquids using filter paper.
What is the role of filter paper in filtration?
Filter paper has tiny holes that allow liquid to pass through while retaining solid particles.
What are the two methods for separating soluble solids from liquids?
The two methods are evaporation and crystallization.
What is the process of evaporation in separating soluble solids?
Evaporation involves heating a solution to evaporate the solvent, leaving behind dry crystals of the solid.
What is a key benefit of using evaporation to separate solids?
Evaporation is a relatively quick and easy method for separating solids from a solution.
What is thermal decomposition?
Thermal decomposition is the process where some solids break down into different substances when heated.
Why is crystallization preferred over evaporation for certain solids?
Crystallization is preferred for solids that may decompose upon heating, as it involves gentler heating.
What is the first step in the crystallization process?
The first step is to place the solution in an evaporation dish and heat it gently.
What happens to a solution as it cools during crystallization?
As the solution cools, more crystals form because solids are less soluble at lower temperatures.
How are crystals separated from the remaining solution after crystallization?
Crystals are separated using filter paper and a funnel.
What is the final step in the crystallization process?
The final step is to dry the crystals, either by leaving them in a warm place or warming them in an oven.
What is the role of a solute in a solution?
The solute is the solid that dissolves in a liquid to form a solution.
What is the role of a solvent in a solution?
The solvent is the liquid in which the solute dissolves to form a solution.
What is the purpose of filtration in separating mixtures?
Filtration separates insoluble solids from liquids using filter paper.
How is the heating method different between evaporation and crystallization?
Evaporation typically uses a Bunsen burner for faster heating, while crystallization uses gentler heating methods, like a water bath.
What equipment is typically used in both evaporation and crystallization?
An evaporating dish or crucible is used for both techniques.
Outline the steps involved in the crystallization process.
- Heat the solution gently; 2. Stop heating when crystals form; 3. Cool to allow more crystals to form; 4. Filter out crystals; 5. Dry the crystals.
What is simple distillation used for?
Simple distillation is used for separating a liquid from a solution, such as obtaining pure water from seawater.
What equipment is needed for simple distillation?
Simple distillation requires a flask, a bung with a thermometer, a condenser, a beaker, and a heating device like a Bunsen burner.
Describe the process of simple distillation.
In simple distillation, the mixture is heated, causing the desired liquid to evaporate, condense in the condenser, and collect in a beaker.
What are the limitations of simple distillation?
Simple distillation is not suitable for separating mixtures of liquids with similar boiling points, as multiple liquids may evaporate together.
What is fractional distillation?
Fractional distillation is the main technique used for separating mixtures of liquids with close boiling points.
What equipment is unique to fractional distillation?
Fractional distillation includes a fractionating column filled with glass rods to increase surface area and create a temperature gradient.
Explain the process of fractional distillation.
In fractional distillation, the mixture is heated, vapors pass through the fractionating column where lower boiling point liquids evaporate first and condense in the condenser.
How does the fractionating column aid in separation?
The fractionating column provides a cooler environment at the top, allowing higher boiling point liquids to condense on the glass rods and return to the flask.
What is the first step in separating methanol, ethanol, and propanol using fractional distillation?
The first step is heating the mixture to around 65°C to evaporate methanol, which has the lowest boiling point.
What happens to ethanol and propanol during the distillation of methanol?
Ethanol and propanol may evaporate but will condense on the cooler glass rods and fall back into the flask.
What are the key pieces of equipment in simple distillation?
Key equipment includes a flask, thermometer, condenser, beaker, and a heating device like a Bunsen burner
Describe the process of simple distillation.
In simple distillation, the mixture is heated, the desired liquid evaporates, cools in the condenser, and collects in a beaker.
What is the limitation of simple distillation?
Simple distillation is not suitable for separating mixtures of liquids with similar boiling points.
What is fractional distillation?
Fractional distillation is the main technique for separating mixtures of liquids with close boiling points.
What is the final step in separating propanol during fractional distillation?
To ensure purity, the temperature can be raised further to boil off the remaining propanol.
What is atomic theory?
Atomic theory is the idea that everything is made up of tiny, indivisible particles called atoms, which are separated by empty space.
Who proposed atomic theory and when?
Atomic theory was proposed by Democritus around 500 BC.
What was John Dalton’s contribution to atomic theory?
John Dalton improved atomic theory in the 1800s by describing atoms as solid spheres, with different types representing different elements.
What did J.J. Thomson discover in 1897?
J.J. Thomson discovered electrons, leading him to propose the plum pudding model of the atom, where electrons are embedded in a positive charge.
What is the plum pudding model?
The plum pudding model suggests that an atom is a ball of positive charge with negatively charged electrons embedded within it.
What experiment did Ernest Rutherford conduct in 1909?
Ernest Rutherford conducted the gold foil experiment, firing alpha particles at a thin gold sheet to study atomic structure.
What were the significant findings of Rutherford’s gold foil experiment?
Rutherford found that most alpha particles passed through the gold, but some were deflected, leading to the conclusion of a compact nucleus.
What is the nuclear model proposed by Rutherford?
The nuclear model proposes that the atom has a compact nucleus containing all positive charge, with electrons in a cloud around it.
What flaw existed in Rutherford’s nuclear model?
The flaw in Rutherford’s nuclear model was the lack of explanation for why electrons do not spiral into the nucleus.
What solution did Niels Bohr propose in 1913?
Niels Bohr proposed that electrons orbit the nucleus in shells, preventing the atom from collapsing.
How do orbiting electrons prevent atomic collapse according to Bohr’s model?
Orbiting electrons maintain a stable arrangement around the nucleus, similar to planets orbiting the sun, preventing collapse.
What did Rutherford discover about the nucleus?
Rutherford discovered that the positive charge in the nucleus is made up of protons.
Who provided evidence for neutrons and when?
James Chadwick provided evidence for neutrons, which are neutral particles in the nucleus.
What is the significance of Rutherford’s nuclear model?
Rutherford’s nuclear model marked a critical advancement in atomic theory by introducing the concept of a nucleus.
What was the timeline of atomic theory development from Democritus to Chadwick?
Democritus proposed atomic theory around 500 BC, Dalton in the 1800s, Thomson in 1897, Rutherford in 1909, Bohr in 1913, and Chadwick later confirmed neutrons.
What is the historical significance of the timeline of atomic theory development?
The historical significance of the timeline of atomic theory development illustrates the progression of scientific thought and experimentation leading to modern atomic models.
How did the concept of empty space relate to atomic theory?
The concept of empty space in atomic theory relates to the idea that atoms are not solid but consist of small particles separated by space.
What did the atomic theories of the 19th century focus on?
The atomic theories of the 19th century focused on the nature of atoms, their composition, and how they combine to form different elements.
How did the understanding of the atom change from Dalton to Bohr?
The understanding of the atom changed from Dalton’s solid sphere model to Bohr’s model of quantized electron orbits around a nucleus.
What is the significance of a full outer shell of electrons in atoms?
Atoms are stable when they have a full outer shell of electrons; otherwise, they tend to react with other atoms to gain or lose electrons.
How many electrons can the first, second, and third shells hold?
The first shell can hold 2 electrons, while the second and third shells can each hold up to 8 electrons.
What is the electron arrangement for sodium (Na)?
Sodium has an atomic number of 11, resulting in an electron arrangement of 2, 8, 1.
Why is sodium considered unstable?
Sodium is unstable because it has only 1 electron in its outer shell instead of the required 8.
What defines noble gases and their reactivity?
Noble gases have completely full outer shells, making them unreactive.
How is the electron arrangement of an element determined?
To determine an element’s electron arrangement, find its atomic number on the periodic table and fill the electron shells according to their capacities.
What is the electron arrangement for argon (Ar)?
Argon has an atomic number of 18, resulting in an electron arrangement of 2, 8, 8.
How can electron structures be represented?
Electron structures can be represented either through diagrams showing shells and electrons or numerically indicating the number of electrons in each shell.
What is an ion?
An ion is an atom or molecule that has a net electric charge due to the loss or gain of electrons.
Why do atoms react with other atoms?
Atoms react with other atoms to achieve a full outer shell of electrons, which is necessary for stability.
What is the maximum number of electrons in the first shell of an atom?
The first shell can hold a maximum of 2 electrons.
How many electrons can the second shell hold?
The second shell can hold up to 8 electrons.
What is the significance of the outermost shell in an atom?
The outermost shell must be completely full for the atom to be stable.
What defines a noble gas?
Noble gases have completely full outer shells, making them unreactive.
How do you determine the electron arrangement of an element?
Find the atomic number on the periodic table, which equals the number of electrons, then fill the shells according to their capacities.
What is the correct order for placing electrons in a shell diagram?
Electrons should be placed in the top, right, bottom, and left positions before pairing them in a clockwise direction.
Who created the periodic table and when?
Dmitri Mendeleev, a Russian chemist, created the periodic table in the mid-19th century.
What does the periodic table organize?
The periodic table organizes all known chemical elements.
What does the atomic number represent?
The atomic number represents the number of protons in the atoms of an element.
What are the three components found in each element box of the periodic table?
Each box contains the elemental symbol, atomic number, and mass number.
What are periods in the periodic table?
Periods are new rows formed every time the pattern of chemical properties of elements repeats.
What are groups in the periodic table?
Groups are vertical columns of elements that have similar chemical properties.
Why do elements in the same group have similar chemical properties?
Elements in the same group have the same number of electrons in their outermost shell.
What is the characteristic of Group 1 elements (Alkali Metals)?
Group 1 elements have one electron in their outer shell and react violently with water.
How does reactivity change within Group 1 elements?
Reactivity of Group 1 elements increases as you move down the group.
What is the characteristic of Group 7 elements (Halogens)?
Group 7 elements have seven electrons in their outer shell and become less reactive as you go down the group.
What defines Group 0 elements (Noble Gases)?
Group 0 elements have full outer shells and are very unreactive due to not needing to gain or lose electrons.
What are transition metals?
Transition metals are a special block of elements found in the middle of the metals in the periodic table.
What is the difference between atomic number and mass number in an element box?
The atomic number is the smaller number representing protons, while the mass number represents the total number of protons and neutrons.
What happens to the reactivity of halogens as you move down the group?
The reactivity of halogens decreases as you move down the group.
How many electrons do Group 2 elements have in their outermost shell?
Group 2 elements have two electrons in their outermost shell.
What is the common property of Noble Gases regarding their electron configuration?
Noble gases have full outer shells, making them very stable and unreactive.
What is the pattern observed by Mendeleev in the periodic table?
Mendeleev observed that elements displayed a repeating pattern of chemical properties at regular intervals.
How is the periodic table typically read?
The periodic table is read from left to right and from top to bottom.
Why might periodic tables appear different?
Periodic tables may appear different due to variations in the position of mass and atomic numbers, but they provide the same information.
What is the significance of the group number in the periodic table?
The group number indicates the number of electrons in the outermost shell of the elements in that group.
What is a key characteristic of alkali metals?
Alkali metals all have one electron in their outermost shell, making them highly reactive.
What do the atomic and mass numbers indicate about an element?
The atomic number indicates the number of protons, while the mass number is the total of protons and neutrons.
What did Dmitri Mendeleev create in the mid-19th century?
Mendeleev created the periodic table, which organizes all known elements and predicts new ones.
How is the atomic number identified in a periodic table?
The atomic number is always the smaller of the two numbers found in an element’s box.
What happens to the position of mass and atomic numbers in different periodic tables?
The position of mass and atomic numbers may be reversed in different periodic tables, but they present the same information.
What type of ions do metals typically form?
Metals typically form positive ions when they react.
How do non-metals differ in ion formation compared to metals?
Non-metals either do not form ions or form negative ions.
Why do elements on the left of the periodic table easily lose electrons?
They have few electrons in their outermost shell, making it easier to lose them and form positive ions.
What is the trend in metal reactivity in the periodic table?
Metals become more reactive towards the bottom of the periodic table.
How does the number of electron shells affect metal reactivity?
More electron shells mean outer electrons are farther from the nucleus, making them easier to lose.
What is metallic bonding?
Metallic bonding is a strong type of bond unique to metals that is responsible for their physical properties.
List some physical properties of metals.
Metals are malleable, good conductors of heat and electricity, shiny, sonorous, and have high melting and boiling points.
How do non-metals typically differ in physical properties from metals?
Non-metals are dull, brittle, poor conductors, have low melting and boiling points, and generally lower densities.
where are transition metals located in the periodic table?
Transition metals are located in the center of the periodic table.
What unique property do transition metals have regarding ion formation?
Transition metals can form more than one ion.
What is a common characteristic of transition metal ions in aqueous solutions?
transition metal ions are often colored in aqueous solutions.
What is a catalyst?
A catalyst is a substance that increases the rate of a chemical reaction without being consumed.
What is the significance of nickel in organic chemistry?
Nickel is used as a catalyst in the hydrogenation of alkenes to produce margarine.
Characteristics of metals in the periodic table
Most elements are metals, located towards the bottom left of the periodic table.
What are the physical properties of alkali metals?
Alkali metals are relatively soft, have low densities, and exhibit low melting points.
How does reactivity trend among alkali metals?
Reactivity increases as you go down the group, with cesium being the most reactive.
What happens when alkali metals react with water?
They react vigorously to produce a metal hydroxide and hydrogen gas.
What is the result of sodium reacting with water?
Sodium reacts with water to form sodium hydroxide and hydrogen gas.
What is the general reaction of alkali metals with chlorine?
they react vigorously to form white metal chloride salts.
How do alkali metals react with oxygen?
They form metal oxides, with the specific type depending on the metal.
What type of oxide does lithium form when reacting with oxygen?
Lithium forms lithium oxide (Li2O) when reacting with oxygen.
What are the physical properties of alkali metals?
Alkali metals are soft, have low densities, and exhibit low melting points.
How does reactivity change among alkali metals as you go down the group?
Reactivity increases as you descend the group, with cesium being the most reactive.
What is the reason for the high reactivity of alkali metals?
Alkali metals have one electron in their outermost shell, which they can easily lose to achieve stability.
What happens to the atomic radius of alkali metals as you move down the group?
The atomic radius increases, causing the outermost electron to be further from the nucleus.
What is the explanation for the reactivity of alkali metals?
Alkali metals have one electron in their outermost shell, which they easily lose to achieve stability.
How does the distance of the outermost electron from the nucleus affect reactivity?
Increased distance weakens the attractive force from the nucleus, making it easier to lose the outer electron.
What type of compounds do alkali metals typically form with non-metals?
Alkali metals typically form ionic compounds with non-metals.
How does atomic radius affect the reactivity of alkali metals?
As atomic radius increases, the outermost electron is further from the nucleus, making it easier to lose, thus increasing reactivity.
What occurs when an alkali metal reacts with water?
An alkali metal reacts vigorously with water to produce a metal hydroxide and hydrogen gas.
What defines the term ‘reactivity’ in chemistry?
Reactivity refers to how easily atoms can lose or gain electrons and react with other atoms.
What type of compounds do alkali metals typically form with non-metals?
Alkali metals typically form ionic compounds with non-metals.
What is a common characteristic of ionic compounds formed by alkali metals?
Ionic compounds formed by alkali metals are generally white solids that dissolve in water to form colorless solutions.
What trend is observed in the reactivity of alkali metals with water as you move down the group?
The reactivity of alkali metals with water increases as you move down the group.
What is a characteristic property of alkali metals when heated in chlorine?
Alkali metals react vigorously with chlorine when heated, forming white metal chloride salts.
What are halogens and their general properties?
Halogens are group 7 elements that are dangerous in some way and exist as diatomic molecules, sharing electrons to form covalent bonds.
What types of compounds do halogens commonly form with alkali metals?
Halogens commonly form ionic compounds with alkali metals, such as sodium chloride.
List the specific halogens and their characteristics.
Fluorine is a poisonous yellow gas; chlorine is a poisonous green gas; bromine is a red-brown volatile liquid; iodine is a dark gray solid that forms poisonous vapors.
What are noble gases and their general properties?
Noble gases are group 0 elements that exist as colorless gases, have full outer shells, are inert, exist as single atoms, and are non-flammable.
What is a halide?
A halide is a one minus ion formed when a halogen gains an electron, changing its name to fluoride, chloride, bromide, or iodide.
What are halogens and their general properties?
Halogens are group 7 elements that are dangerous in some way and exist as diatomic molecules, sharing electrons to form covalent bonds.
What is a halide and how is it formed?
A halide is a one minus ion formed when a halogen gains an electron, resulting in names like fluoride, chloride, bromide, and iodide.
What is a displacement reaction in the context of halogens?
A displacement reaction occurs when a more reactive halogen displaces a less reactive one from a compound.
What trend occurs in melting and boiling points as you go down the halogen group?
Melting points and boiling points increase as you go down the group of halogens.
What are displacement reactions in the context of halogens?
Displacement reactions occur when a more reactive halogen displaces a less reactive one, such as chlorine displacing bromide in potassium bromide.
How do the boiling points of noble gases change as you go down the group?
Boiling points of noble gases increase as you go down the group.
What trend occurs in boiling points as you go down the noble gas group?
Boiling points increase as you go down the group of noble gases.
With which group do halogens often form ionic compounds?
Halogens often form ionic compounds with alkali metals in Group 1, such as sodium chloride.
List the four main halogens and their characteristics.
Fluorine is a poisonous yellow gas and very reactive; chlorine is a poisonous green gas and less reactive; bromine is a red-brown volatile liquid and poisonous; iodine is a dark gray solid that forms poisonous vapors and is also an antiseptic.
What trend occurs in melting and boiling points as you go down Group 7 (halogens)?
Melting points and boiling points increase as you go down the group.
What are halogens and their general properties?
Halogens are Group 7 elements that are dangerous and exist as diatomic molecules, achieving this by sharing electrons to form covalent bonds.
