Matter & Elements and Electrons & Bonding (Unit 1) Flashcards
the more—– an electron is from the nucleus, the ——- its potential energy.
the more distant an electron is from the nucleus, the greater its potential energy.
What is matter?
Anything that has mass and takes up space.
What is matter made up of?
Matter is made up of elements.
What is an element?
An element is a substance that cannot be broken down to other substances by chemical reactions.
What are the three main states of matter?
Liquid, Solid, Gas.
What characterizes solid matter?
Regularly arranged particles that are close enough together and cannot be penetrated.
What characterizes liquid matter?
No regular arrangement and takes the shape of their container.
What characterizes gas matter?
Takes the shape of the container with particles that are far apart.
How does matter interact with the environment?
Matter cycles between an organism and its environment.
What is vaporization?
The process of changing from a liquid to a gas.
What is condensation?
The process of changing from a gas to a liquid.
What is melting?
The process of changing from a solid to a liquid.
What is freezing?
The process of changing from a liquid to a solid.
What is sublimation?
The process of changing from a solid to a gas.
What is deposition?
The process of changing from a gas to a solid.
Where does deposition often happen?
In the environment when things in the air become part of something solid.
What is an atom?
The basic unit of matter.
What are the three main types of subatomic particles?
Protons, neutrons, and electrons.
What charge do protons have?
Protons are positively charged.
What role do protons play in an atom?
Protons determine an atom’s identity.
What charge do neutrons have?
Neutrons have no charge.
What charge do electrons have?
Electrons are negatively charged.
Where are protons and neutrons located in an atom?
Protons and neutrons assemble in the nucleus.
What is usually true about the number of protons and neutrons in an atom?
Usually, the number of protons equals the number of neutrons.
What charge does the nucleus of an atom have?
The nucleus has a positive charge due to protons.
Where do electrons orbit in an atom?
Electrons orbit in shells or orbitals.
What is usually true about the number of electrons and protons in an atom?
Usually, the number of electrons equals the number of protons.
What can atoms lose or gain?
Atoms may lose or gain electrons and/or neutrons.
What are ions?
Ions are atoms that have gained or lost electrons.
What is a cation?
A cation is positively charged because it has lost an electron.
What is an anion?
An anion is negatively charged because it has gained an electron.
What are isotopes?
Isotopes are atoms that have gained or lost neutrons.
Why are isotopes important?
Isotopes are very important in medicine.
What is one application of isotopes?
Understanding the age in a fossil (carbon-14 dating) is one application of isotopes.
What are elements?
Specific types of atoms with specific number of protons, neutrons, and electrons. Elements are stable.
How are elements arranged in the periodic table?
Elements are arranged into order based on weight, electron configuration, etc.
What do rows in the periodic table represent?
Rows represent periods.
What do columns in the periodic table represent?
Columns represent groups.
What information is provided in the square for a particular element?
It tells us the number of protons, neutrons, electrons, and the element’s weight.
What is atomic number?
The number of protons in an atom of a specific element. Also the number of electrons in an electrically neutral atom.
What is mass number (atomic mass)?
The number of protons plus neutrons.
What is the approximate weight of protons and neutrons?
Protons and neutrons weigh about the same amount.
What is the weight of electrons?
Electrons are basically weightless.
What are organisms made up of?
Organisms are made up of elements.
What are the two categories of elements?
Essential Elements and Non-essential Elements.
What are essential elements?
Elements that an organism must have to survive.
What are non-essential elements?
Elements that are nice to have, but not absolutely necessary.
What are the general essential elements for living organisms?
All living organisms must have six elements at a minimum: SPONCH.
What do SPONCH elements make up?
SPONCH elements make up macromolecules.
Do most organisms need more than just the six essential elements?
Yes, most organisms need more than just these six.
What are specific essential elements?
Specific essential elements are variable and depend on the organism.
What is the quantity requirement for macronutrients?
Macronutrients are elements an organism needs in large amounts.
What are trace elements?
Trace elements, also known as micronutrients, are required in small amounts.
What does SPONCH stand for?
Sulfur, Phosphorus, Oxygen, Nitrogen, Carbon, Hydrogen
What are electrons?
Electrons are energetic particles and the source of energy for living things.
What is the role of electrons in chemical reactions?
Electrons are the only subatomic particles involved in chemical reactions.
How do electrons orbit the nucleus?
Electrons orbit the nucleus in shells/orbitals.
What determines the number of electrons in each shell?
Each shell has a set number of electrons it can hold.
How do simple and complex atoms differ in terms of shells?
Simple atoms have few shells and few electrons, while complex atoms have many shells and many electrons.
What is the capacity of Shell 1?
Shell 1 can hold up to 2 electrons.
What is the capacity of Shells 2 and 3?
Shells 2 and 3 can each hold up to 8 electrons.
What is the outermost shell of an atom called?
The outermost shell is called the Valence shell.
What are valence electrons?
Valence electrons are the electrons that are in the outermost shell.
What is the valence number?
The valence number is the number of electrons in the valence shell.
Provide examples of valence shells and numbers for Lithium, Beryllium, and Boron.
Lithium (valence shell 2, valence number 1), Beryllium (valence shell 2, valence number 2), Boron (valence shell 2, valence number 3).
What role do valence electrons play in chemical reactions?
Valence electrons play a big role in how an atom will react in an environment and in what ways it can combine with other elements.
What do atoms prefer regarding their valence shells?
Atoms prefer full valence shells.
Shell 1 should have 2 electrons.
Shells 2 and 3 should have 8 electrons.
What happens to atoms with full valence shells?
Atoms with full valence shells tend not to react with others.
What happens to atoms without full valence shells?
Atoms without full valence shells tend to react with others to join with other atoms and make full shells.
What causes chemical bonds to form?
Chemical bonds form when the electrons of two or more atoms interact with each other.
What are the three main functions of chemical bonds?
- Allow atoms to be held together
- Store energy
- Form stable compounds
What are the three main types of chemical bonds?
- Covalent Bonds-Sharing of electrons
- Ionic Bonds – Transfer of electrons
- Hydrogen Bonds – Weak associations
- Van der waals -not a real bond
What are Van der Waals interactions?
Weak forces that occur due to temporary shifts in electron distribution in atoms or molecules.
What is a covalent bond?
A strong bond where two atoms share electrons so that each has a full outer shell.
What is the strongest type of chemical bond?
Covalent bonds.
What is the difference between single and double covalent bonds?
Single bond:** Shares one pair of electrons
- Double bond: Shares two pairs of electrons
What is the difference between polar and nonpolar covalent bonds?
- Polar bonds: Unequal sharing of electrons
- Nonpolar bonds: Equal sharing of electrons
Where do electrons spend most of their time in a polar covalent bond?
Electrons spend more time around the more electronegative atom, creating a negative pull.
What is electronegativity?
A measure of how strongly an atom pulls electrons toward itself in a bond.
How does electronegativity change across the periodic table?
It increases from left to right and bottom to top on the periodic table.
What happens in an ionic bond?
One atom transfers an electron to another atom, forming cations and anions.
How strong are ionic bonds?
They are medium strength and break easily.
What does an ionic bond create?
An ionic compound made of positively and negatively charged ions.
What is a hydrogen bond?
A weak interaction between hydrogen and a highly electronegative atom (O, N, F). <—Oxygen, nitrogen, flouride
Where do hydrogen bonds occur?
Between molecules, not within them. Holding molecules together.
What are two important roles of hydrogen bonds?
- Responsible for certain properties of water
- Help hold DNA together
What are Van der Waals interactions?
Weakest** type of interaction, where positive and negative regions of molecules attract each other.
Why can geckos walk on flat surfaces?
Because of Van der Waals interactions.
Do molecules touch in Van der Waals interactions?
No, they never touch, but experience constant push-pull forces.
What is a chemical reaction?
A process that rearranges atoms or molecules.
How is a chemical reaction written?
Left to right with reactants on the left and products on the right.
What are the three types of chemical reactions?
- Synthesis (A + B → AB)
- Decomposition (AB → A + B)
- Exchange/Replacement (AB + C → AC + B)
What is a synthesis reaction?
A reaction that puts things together (often called a dehydration reaction). (A+B–>AB)
What is a decomposition reaction?
A reaction that breaks things apart (often called a hydrolysis reaction).
(AB–>A+B)
What is an exchange/replacement reaction?
A reaction where components are rearranged in a compound.
(AB + C → AC + B)
What is a compound?
A substance made of atoms joined by bonds.
-molecular compound
The three-dimensional space where an electron is found 90% of the time is called an
orbital
Two or more atoms held together by covalent bonds constitute a
molecule
-Its molecular formula H2 simply indicates that the molecule consists of two atoms of hydrogen.
