WorksheetsMolecules and Compounds
Total questions: 20
Worksheet time: 11mins
Name
Class
Date
1.
Why is it impossible to see molecules with the naked eye?
a)
they are too big
b)
they are too small
c)
they are too fast
d)
they have no mass
2.
Which of these compounds has the most atoms?
a)
CO2
b)
C6,H12,O6
c)
O2
d)
Na,Cl,He,O3
3.
The separation of ions that occurs when an ionic compound dissolves in a solution is known as
a)
association
b)
dissociation
c)
associative principle
d)
molecular association
4.
At room temperature, oxygen is a gas and hydrogen is a gas. When they combine, they form a
a)
solid
b)
liquid
c)
gas
d)
solution
5.
A water molecule contains
a)
one hydrogen atom and two oxygen atoms
b)
two hydrogen atoms and one oxygen atom
c)
two hydrogen atoms and two oxygen atoms
d)
two hydrogen atoms and no oxygen atoms
6.
___________ are completely different from the elements they are made of.
a)
compounds
b)
atoms
c)
elements
d)
ions
7.
Sodium can burn and chlorine can kill you. When they combine into a molecule, the new substance is
a)
a solid that is safe to touch
b)
an explosive solid that must be handled carefully
c)
a combination of gasses that can be deadly
d)
a neutral gas that is safe to breathe
8.
The formula CO represents one __________ of carbon monoxide.
a)
atom
b)
molecule
c)
ion
d)
isotope
9.
A molecule of H2,S,O4 contains how many atoms?
a)
3
b)
6
c)
7
d)
8
10.
Table salt dissolves in water. What happens when saltwater is made?
a)
the salt crystals sink to the bottom of the water
b)
the ionic compound (salt) breaks into pieces
c)
the salt crystals float to the top of the water
d)
the water molecules split into ions
11.
Carbon dioxide (CO2) contains carbon and oxygen. For a molecule to form ____________.
a)
one carbon atom combines with two oxygen atoms
b)
one oxygen atom combines with two carbon atoms
c)
one carbon atom combines with one oxygen atom
d)
two carbon atoms combine with two oxygen atoms
12.
What is the common name for H2O?
a)
salt
b)
acid
c)
base
d)
water
13.
Compounds form when ________________.
a)
atoms of one element bond
b)
atoms of two or more elements bond
c)
molecules of one element are mixed together
d)
molecules of two or more elements are mixed together
14.
What is the difference between elements and compounds?
a)
elements have more than one kind of atom while compounds have only one kind of atom
b)
elements can separate by physical means while compounds cannot
c)
compounds have more than one kind of atom while elements have only one kind of atom
d)
elements are acids while compounds are bases
15.
What is the chemical name for CO2?
a)
carbon trioxide
b)
carbon monoxide
c)
carbon dioxide
d)
methane
16.
What is the common name for NaCl?
a)
salt
b)
acid
c)
base
d)
water
17.
Which of the following IS a molecule but is NOT a compound?
a)
CO2
b)
C
c)
O2
d)
CO
18.
Which of these elements is the basis for all life?
a)
hydrogen
b)
oxygen
c)
carbon
d)
sodium
19.
When one atom loses an electron and becomes positive and another atom gains an electron and becomes negative, they stick together like magnets. What is this called?
a)
ionic bond
b)
covalent bond
c)
molecular bond
d)
atomic bond
20.
When one atom tries to take another atom's electron and that atom wont let go, both atoms are now holding on to that electron like links in a chain. What is this called?
a)
ionic bond
b)
covalent bond
c)
molecular bond
d)
atomic bond
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