Text A Chemistry 1.3 Electrons And The Formation Of Compounds Flashcards
What happens when a mixture of hydrogen and oxygen is ignited?
It burns explosively, forming water.
What are the physical and chemical properties of water compared to hydrogen and oxygen?
They are different from those of the two original elements.
What is the formula for the compound formed by hydrogen and oxygen?
H₂O
What does the periodic table arrange elements into?
Periods (horizontal rows) and groups (vertical columns).
How do elements appear across periods in the periodic table?
In order of their atomic number.
What are groups of elements also called?
Families.
What are elements in group I called?
Alkali metals.
What are elements in group 2 called?
Alkaline earth metals.
What are elements in group 17 called?
Halogens.
What are elements in group 18 called?
Noble gases or inert gases.
What does the dark ‘staircase’ line in the periodic table indicate?
It separates metals from non-metals.
What are elements that border the staircase line called?
Metalloids.
What are the characteristic physical states of metals at room temperature?
Solids, except for mercury (a liquid).
What is the physical state of non-metals at room temperature?
Some are gases, and some are solids.
What is the conductivity of metals?
Good conductors of heat and electricity.
What is the conductivity of metalloids?
Poor conductors of heat and electricity.
What is the malleability and ductility of metals?
Malleable and ductile.
What is the malleability and ductility of non-metals?
Brittle and not ductile.
What is the appearance of metals?
Shiny lustre.
What is the appearance of non-metals?
Some are shiny, others are dull.
Fill in the blank: Elements in group 3 to 12 are known as _______.
Transition metals.
What are the Group 18 elements known as?
Noble gases
Why are noble gases unlikely to take part in chemical reactions?
They have a full complement of electrons in their outermost energy level.
What does the periodic table represent?
Patterns related to the arrangement of electrons in atoms.
How can the periodic table help predict chemical behavior?
It helps explain how substances behave during a chemical change.
What did Neils Bohr infer about electrons?
Electrons orbit the nucleus of the atom in fixed energy levels.
What is the maximum number of electrons the first energy level can hold?
Two electrons
What is the maximum number of electrons the second energy level can hold?
Eight electrons
How many occupied energy levels do the elements in period 1 have?
One occupied energy level
Which element in period 1 has a full complement of electrons?
Helium
How many electrons does hydrogen have in its first energy level?
One electron
What is the arrangement of electrons in the outermost occupied energy level called?
Stable octet
What is the maximum number of electrons in the outer occupied energy level of period 3 elements?
Eight electrons
What happens to the number of electrons in the second energy level as you move across period 2?
One more electron is added to the second energy level of each atom.
What is the significance of neon in relation to period 2?
It has the maximum of eight electrons in its second energy level.
Fill in the blank: The _______ is the number of occupied energy levels of an element’s atoms.
[period number]
What determines the group-related pattern of the periodic table?
The number of electrons in the outer occupied energy level.
How many electrons do group 1 elements have in their outer occupied energy level?
One electron.
How many electrons do group 2 elements have in their outer occupied energy level?
Two electrons.
What is the outermost occupied energy level of an atom called?
Valence energy level.
What are the electrons in the valence energy level called?
Valence electrons.
Which group of elements has a filled outer energy level?
Group 18 elements.
How many valence electrons does helium have?
Two electrons.
How many valence electrons do neon and argon have?
Eight electrons.
What is the group name for group 1?
Alkali metals.
What is the group name for group 2?
Alkaline earth metals.
What is the group name for group 17?
Halogens.
What is the group name for group 18?
Noble gases.
What is the appearance of alkali metals?
Shiny solids.
What are the physical states of halogens?
Chlorine and fluorine are gases, bromine is a liquid, iodine is a solid.
What is the expected appearance of sodium (Na)?
Very soft, malleable, and ductile.
What do alkali metals react easily with?
Water and other substances.
What do alkali metals react with oxygen to form?
Oxides.
What do alkali metals react with metallic elements to form?
Salts.
Identify the number of valence electrons for chlorine (Cl)
Seven valence electrons.
Identify the number of valence electrons for magnesium (Mg)
Two valence electrons.
Fill in the blank: Group 2 elements have _______ valence electrons.
2
Fill in the blank: Group 18 elements have _______ valence electrons.
8
What is the group number for alkaline earth metals?
Group 2.
What is the group number for halogens?
Group 17.
What is the group number for noble gases?
Group 18.
What is the expected appearance of iodine (I)?
Solid.
What do electron dot diagrams represent?
An atom and its valence electrons
Electron dot diagrams visually depict the outermost electrons of an atom.
What does the symbol of the element stand for in an electron dot diagram?
The nucleus and inner energy level electrons of the atom
This representation helps to focus on the valence electrons.
What are the valence electrons shown as in an electron dot diagram?
Dots placed around the symbol
Each dot represents one valence electron.
Who is honored by the term ‘Lewis diagrams’?
Gilbert Newton Lewis
He was an American chemist who first used these diagrams.
True or False: Electron dot diagrams are only used for lithium and fluorine.
False
Electron dot diagrams can be used for any element to represent its valence electrons.
Fill in the blank: Electron dot diagrams are also called _______.
[Lewis diagrams]
What is the charge of a neutral atom?
No net charge.
What is an ion?
An atom or group of atoms that carries a positive or negative electrical charge.
What is a positively charged ion called?
Cation.
How does a cation form?
When an atom loses electrons.
What is the relationship between protons and electrons in a cation?
More protons than electrons.
What is the charge of a negatively charged ion?
Negative.
What is a negatively charged ion called?
Anion.
How does an anion form?
When an atom gains electrons.
What is the relationship between protons and electrons in an anion?
More electrons than protons.
What suffix do non-metal ion names typically end in?
-ide.
What is the name of a negatively charged fluorine atom?
Fluoride anion.
What happens to a neutral sodium atom when it loses an electron?
It becomes a positively charged sodium ion.
What is the number of protons in a neutral sodium atom?
11 protons.
What is the number of electrons in a neutral chlorine atom?
17 electrons.
What happens to a neutral chlorine atom when it gains an electron?
It becomes a negatively charged chloride ion.
Fill in the blank: A positively charged ion has _______ electrons than protons.
fewer.
Fill in the blank: A negatively charged ion has _______ electrons than protons.
more.
True or False: The names of ions of metal elements are different from the names of the elements.
False.
What is the symbol for a sodium ion?
Na+
What is the symbol for a chloride ion?
Cl-
What is the charge of a magnesium ion?
Mg2+
How are ions represented in chemistry?
Using their charge and the symbol of the element from which they are formed.
What happens during the transfer of electrons between atoms?
One atom loses an electron while another atom accepts it, forming a compound.
Why do atoms tend to form compounds?
To achieve a full valence energy level similar to noble gases.
What is the relationship between chemical stability and valence electrons?
A full valence energy level leads to greater chemical stability.
What occurs when two atoms collide regarding their valence electrons?
Their valence electrons interact, and a chemical bond forms if the arrangement is stable.
What are the three ways an atom may acquire a noble gas configuration?
- Metallic atoms give up electrons to form cations
- Non-metallic atoms accept electrons to form anions
- Non-metallic atoms share electrons
What are ionic compounds?
Compounds composed of ions.
What are binary ionic compounds?
Ionic compounds formed from just two elements.
How do neutral atoms become charged ions in a binary ionic compound?
Metal atoms transfer valence electrons to non-metal atoms.
What holds the ions in ionic compounds together?
Ionic bonds formed by the attraction between oppositely charged ions.
What happens when sodium metal reacts with chlorine gas?
A cloud of fine white particles appears and the sodium shrinks and vanishes.
What types of ions are found in sodium chloride (NaCl)?
- Sodium ions (Na+) with a charge of 1+
- Chloride ions (Cl-) with a charge of 1-
Fill in the blank: Compounds formed from ions are called _______.
ionic compounds
True or False: Ionic bonds are weak due to the forces of attraction between ions.
False
What is the repeating pattern of ions in an ionic compound called?
Crystal lattice
The crystal lattice is a regular arrangement of ions held together by ionic bonds.
How are ions in sodium chloride arranged?
In a regular, repeating pattern
This arrangement is known as a crystal lattice.
What holds the ions in an ionic compound rigidly in place?
Strong ionic bonds
Ionic bonds result from the electrostatic attraction between oppositely charged ions.
What is the electron configuration of a sodium ion, Na+?
Same as a neon atom
Na+ has a completed valence energy level similar to that of the nearest noble gas, neon.
Which noble gas is closest to sodium, magnesium, and aluminum?
Neon
These elements’ cations have the same number of electrons as neon.
What is the electron configuration of the chloride ion, Cl-?
Same as an atom of argon
Cl- has a completed valence energy level similar to that of argon.
What forms binary ionic compounds?
Electrons are transferred from metal atoms to non-metal atoms
This electron transfer results in the formation of cations and anions.
What do anions and cations in ionic compounds form?
A crystal lattice
Ionic bonds hold these ions together in a structured arrangement.
What happens when coal burns in oxygen?
Atoms of carbon and oxygen form bonds
This reaction produces carbon dioxide, which is a molecular compound.
What are groups of atoms that share electrons called?
Molecules
Molecular compounds are composed of these groups of atoms.
What are compounds composed of molecules called?
Molecular compounds
Examples include carbon dioxide and other compounds with only non-metal elements.
What type of bonds join atoms in molecules?
Covalent bonds
Covalent bonds involve the sharing of electrons between non-metal atoms.
How do atoms in a molecular compound tend to behave regarding electrons?
They tend to gain electrons
This is to complete their valence energy level without easily giving up electrons.
What is the result when atoms interact in a molecular compound?
No electron transfer is likely to take place
This leads to the formation of molecules rather than ions.
What are diatomic molecules?
Molecules composed of two atoms
Examples include O2 (oxygen) and H2 (hydrogen).
List three examples of diatomic elements.
- Oxygen (O2)
- Hydrogen (H2)
- Nitrogen (N2)
Diatomic elements exist as pairs of atoms.
What is the chemical formula for sulfur?
S8
Sulfur exists as a polyatomic molecule composed of eight atoms.
What is a covalent bond?
A covalent bond is formed when two atoms share a pair of electrons, one from each atom.
What type of bond is formed when two atoms share two pairs of electrons?
A double covalent bond.
What is the formula for water?
H2O.
How many electrons does the oxygen atom need in a water molecule?
Two more electrons.
What do electron dot diagrams represent?
Electron sharing in molecules.
What is the stable electron configuration achieved through?
Electron sharing.
True or False: Molecular compounds form a crystal lattice like ionic compounds.
False.
What do you call the independent units that make up molecular compounds?
Molecules.
Fill in the blank: Molecular compounds form when non-metal atoms share one or more pairs of ______.
Electrons.
What is a triple covalent bond?
A bond where two atoms share three pairs of electrons.
What is the challenge in predicting the formation of carbon monoxide (CO)?
It is difficult to show how the atoms achieve a stable octet.
What does carbon require to achieve a stable octet?
Four electrons.
What does oxygen require to achieve a stable octet?
Two electrons.
What happens when substances are burned without sufficient oxygen?
Carbon monoxide, a toxic compound, builds up.
What is the difference between molecular compounds and ionic compounds?
Molecular compounds consist of molecules, while ionic compounds form a crystal lattice.
What can you predict by examining the arrangement of electrons in an atom’s valence energy level?
The number of covalent bonds an atom will form.
What type of bond does chlorine gas (Cl2) have?
A single covalent bond.
What do valence electrons affect in atoms?
They affect the ways that elements combine to form ionic and molecular compounds.
What will you learn in the next chapter after examining valence electrons?
Rules for naming compounds and writing their formulas.
What is the total number of electrons in an atom of rubidium (Rb)?
37
How many occupied energy levels does a rubidium atom have?
5
How many electrons are in the valence energy level of a rubidium atom?
1
What is the symbol for the ion that rubidium would form in an ionic compound?
Rb⁺
Why is knowing the number of electrons in the valence energy level of an atom important?
It helps predict how the atom will bond with other atoms.
How is the number of valence electrons in an atom related to its position in the periodic table?
Elements in the same group have the same number of valence electrons.
What is the total charge on one fluoride ion?
-1
What is the total charge on one sulfide anion?
-2
What is the total charge on two nitride anions?
-6
Name two cations and two anions that have the same number of electrons as an atom of argon.
- Cations: K⁺, Ca²⁺
- Anions: Cl⁻, S²⁻
What bonding occurs between magnesium and oxygen?
Ionic bonding
What bonding occurs between nitrogen and hydrogen?
Covalent bonding
Which element or elements from the electron dot diagrams are non-metals?
Elements with more than four valence electrons.
Which element will not combine with oxygen and why?
The element with a full valence shell.
If an unknown element exists as ions with a 2- charge, is it a metal or a non-metal?
Non-metal
Where in the periodic table would you expect to find an element with a 2- charge?
Group 16
