WorksheetsTest Practice: Compounds, Formulas, and Reactions
Total questions: 40
Worksheet time: 26mins
Why do all bonds form?
to fill the outermost energy level
so an atom can be unstable
so the number of protons and electrons can equal.
so they can gain neutrons.
Valence electrons are found
outermost energy level
innermost energy level
some where in the electron cloud
An atom with 1 valence electron 'needs' a full shell, so it can either gain 7 electrons or lose 1. Which is more likely to occur?
nothing
gain 7
lose 1
What two types of atoms make a covalent bond?
2 nonmetals
2 metals
1 metal and 1 nonmetal`
When an atom loses an electron, it becomes a
positive ion
negative ion
Ionic bonds are between
metals and nonmetals
2 metals
2 nonmetals
When two nonmetals do not share electrons evenly, the resulting covalent bond will be
nonpolar
polar
ionic
metallic
Which category of elements usually form negative ions?
metals
nonmetals
metalloids
noble gases
Cations
Gain electrons, has an overall positive charge
Lose electrons, has an overall positive charge
Lose electrons, has an overall negative charge
Gain electrons, has an overall negative charge
The first step in naming an ionic compound is always...
Naming the anion (non-metal)
Changing the ending to -ide
Naming the cation (metal)
Writing the cation charge
Na2S
Molecules:
have covalent bonds and are always polar
have covalent bonds and are always non-polar
have covalent bonds and can be polar or non-polar
have ionic bonds and are always polar
The following properties are all characteristics of ionic compounds EXCEPT
solid at room temperature
soft
crystal lattice structure
conduct electricity when dissolved in water
Which set of elements is most likely to form an ionic compound?
Na and O
C and O
Na and K
Which of the following describes covalent bonds?
Bonds form because of opposite charges
electrons are shared to fill outer electron shells
Electrons are transferred between atoms
Covalent bonds are magical
Is the following compound ionic or covalent?
PBr5
Ionic
Covalent
Is the following compound ionic or covalent?
A material with a high melting point
Ionic
Covalent
Which is NOT a property of covalent compound?
It has low melting point
It exists in a stable crystalline structure.
It does not exhibit any electrical conductivity.
It is usually solid at normal temperature and pressure.
Which gives the best explanation of why a solid ionic compound DOES NOT conduct electricity?
Solid ionic compounds do not have ions.
Solid ionic compounds are not soluble in water.
Solid ionic compounds have ions which are free to move.
Solid ionic compounds have ions, but these ions are not free to move.
Why do ionic compounds conduct electricity when dissolved in water, but most covalent compounds do not?
Covalent compounds have lower melting point than ionic compounds.
Covalent compounds are weakly bonded while ionic compounds are strongly bonded.
Covalent compounds do not dissolve in water since they are composed of non- polar molecules.
Covalent compounds dissolve into molecules, while ionic compounds dissolve into ions that conduct charge.
The figure below represents the arrangement of particles in a substance. What kind of substance is this?
Ionic compound
Metallic compound
Covalent compound
None of these
Which are the reactants in this chemical equation?
Left side
Right side
Which are the products in this chemical equation?
CH4
CH4 + 2O2
CO2 + 2H2O
2H2O
How many Oxygen atoms are in the reactant side in this chemical reaction?
4
6
1
Is this chemical equation balanced or unbalanced?
balanced
unbalanced
Which is the least likely evidence that a chemical reaction occurred?
color
sound
light
temperature
A chemical equations is considered balanced when
reactants break apart
products are greater than reactants
reactants = products
when the chemical reaction happens
Place _________ in front of the formulas as needed to balance the equation.
states of matter
subscripts
coefficients
_________can never be changed, since this would change the identity of the compounds
subscripts
superscripts
coefficients
chemical formulas
The coefficient in 3H2O is
6
5
2
3
4
8
N2+O2--> _NO
Balance this equation
_Al +_HCl --> _H2 +_AlCl3
2,6,3,2
it's already balanced
4,12,3,4
2,1,4,5
If 40g of substance A and 50 g of substance B are combined in a chemical reaction, they produce 70 g of substance C and an unknown amount of substance D. How many grams of substance D are theoretically produced?
50g
40g
20g
None of these/Not enough info
Balance the equation Fe3O4+H2−>Fe+H2O.
3,1,4,2
1,4,3,4
2,8,6,8
none of the above
What best describes what happens during a chemical reaction?
New atoms are created from other atoms
Multiple substances are always combined to make 1 new substance.
Existing atoms are rearranged to produce new substances.
Atoms in the reactants are destroyed and replaced by new atoms.
