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WorksheetsIntroduction to Chemistry of Life
Total questions: 20
Worksheet time: 10mins
Name
Class
Date
1.
Which of the following statements is incorrect?
a)
Matter may be solid, liquid or gas.
b)
Elements can be decomposed into simpler substances by ordinary chemical reactions.
c)
A compound is any substance composed of atoms of two or more different elements that are chemically combined
d)
A molecule is the combination of two or more atoms held together by covalent bonds.
2.
Which of the following statements is not true?
a)
Protons are positively charged particles which contribute to the weight of an atom.
b)
The overall charge of the atom’s nucleus is always positive.
c)
The number of electrons always equals the number of protons in a neutral atom.
d)
The bigger difference in neutrons in the isotope, the more stable it becomes.
3.
A cation is formed when an atom loses an electron or electrons to another atom creating an overall positive charge.
a)
True
b)
False
4.
The atomic number refers to the
a)
mass of an atom
b)
number of protons in an atom
c)
number of both protons and neutrons in an atom
d)
number of neutrons in an atom
5.
Radioactive isotopes have an excess number of neutrons.
a)
True
b)
False
6.
Which of the following is not a compound?
a)
NaCl
b)
C6H1206
c)
H20
d)
o2
7.
The negative subatomic particle in an atom is the
a)
neutron
b)
proton
c)
electron
d)
both neutrons and electrons
8.
The nucleus of an atom contains
a)
neutrons and protons
b)
neutrons and electrons
c)
protons and electrons
d)
protons only
9.
The atomic weight of an atom is determined by the weight of
a)
neutrons and protons
b)
neutrons and electrons
c)
protons and electrons
d)
neutrons only
10.
Magnesium has 12 protons. How many electrons are in the third energy level?
a)
2
b)
4
c)
6
d)
8
11.
Nitrogen has an atomic number of 7. How many hydrogen atoms are necessary to join with the nitrogen to form a stable compound?
a)
1
b)
2
c)
3
d)
4
12.
A molecule is
a)
a combination of two or more atoms
b)
less stable than its constituent atoms separated
c)
electrically charged
d)
a carrier of one or more extra neutrons
13.
What is formed when an atom loses or gains an electron?
a)
mole
b)
ion
c)
molecule
d)
bond
14.
An element that gains an electron has been
a)
oxidized
b)
reduced
15.
When an atom loses an electron, it becomes negatively charged.
a)
True
b)
False
16.
In ____ bonds, both atoms exert the same pull on shared electrons.
a)
nonpolar covalent
b)
polar covalent
c)
double covalent
d)
triple covalent
17.
Which of these statements is false concerning covalent bonds?
a)
atoms share electrons
b)
proteins possess many covalent bonds
c)
water contains polar covalent bonds
d)
polar covalent bonds share electrons equally
18.
A hydrogen bond is a weak bond between two molecules resulting from an electrostatic attraction between a proton in one molecule and an electronegative atom in the other.
a)
True
b)
False
19.
Which of the following is true of water?
a)
the oxygen end is slightly electropositive
b)
hydrogen bonds hold water molecules together
c)
water molecules are joined through polar covalent bonds
d)
water is a solid at room temperature
20.
Which of the following statements about water is false?
a)
The polar covalent bonds between the hydrogens and oxygen of water molecule is due to the high electronegativity of oxygen
b)
Water is the universal solute
c)
Water has cohesive and adhesive properties
d)
Water has a high specific heat and a high rate of evaporation due to hydrogen bonds
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