WorksheetsCHM090_Ch1_Review
Total questions: 25
Worksheet time: 16mins
Which of the following is a subatomic particle found in the nucleus of an atom and has no electric charge?
Proton
Neutron
Electron
Positron
What does the atomic number of an element represent?
The number of neutrons in the atom
The number of protons in the atom
The number of electrons in the atom
The sum of protons and neutrons
Which of the following best defines an isotope?
Atoms with the same number of protons but different numbers of neutrons
Atoms with different numbers of protons and electrons
Atoms with the same number of neutrons but different numbers of protons
Atoms with the same mass number but different atomic numbers
What is the smallest unit of a chemical element that retains its chemical properties?
Molecule
Atom
Compound
Ion
Which of the following is a compound?
O 2
H 2
H 2 O
N 2
Which statement correctly describes a molecule?
A molecule is a single atom of an element.
A molecule is a group of two or more atoms chemically bonded together.
A molecule is a mixture of different elements.
A molecule is always a compound.
Which of the following is true about elements in the same group of the periodic table?
They have the same number of protons.
They have similar chemical properties.
They have the same atomic mass.
They have the same number of neutrons.
If an atom has 11 protons, 12 neutrons, and 11 electrons, what is its mass number?
11
12
22
23
A sample of chlorine contains 75% 35 Cl (atomic mass = 34.97 u) and 25% 37 Cl (atomic mass = 36.97 u). Calculate the average atomic mass of chlorine. Show your work.
35.48 u
35.97 u
36.48 u
36.97 u
Magnesium has three naturally occurring isotopes: 24 Mg (78.99%, mass = 23.99 u), 25 Mg (10.00%, mass = 24.99 u), and 26 Mg (11.01%, mass = 25.98 u). Calculate the average atomic mass of magnesium. Show your work.
24.31 u
24.99 u
25.98 u
23.99 u
Boron has two isotopes: 10 B (19.9%, mass = 10.01 u) and 11 B (80.1%, mass = 11.01 u). Calculate the average atomic mass of boron. Show your work.
10.81 u
10.01 u
11.01 u
10.50 u
A neutral atom of sulfur has an atomic number of 16 and a mass number of 32. How many protons, neutrons, and electrons does it have?
16 protons, 16 neutrons, 16 electrons
16 protons, 32 neutrons, 16 electrons
16 protons, 16 neutrons, 32 electrons
32 protons, 16 neutrons, 16 electrons
Which of the following statements best explains why isotopes of the same element have nearly identical chemical properties?
Because they have the same number of neutrons.
Because they have the same number of protons and electrons.
Because they have the same mass number.
Because they have different numbers of protons.
A student claims that the atomic mass of an element is always a whole number. Use your knowledge of isotopes and atomic mass calculations to evaluate this claim.
The claim is correct because atomic mass is the sum of protons and neutrons.
The claim is incorrect because atomic mass is a weighted average of all isotopes, which is usually not a whole number.
The claim is correct because all isotopes have the same mass.
The claim is incorrect because atomic mass is always less than 1.
Match the following
number of protons & electrons
18
number of neutrons
22
mass number
40
How many neutrons are in the nucleus of a potassium atom with a mass number of 39?
Lithium-7 has 3 (a) and 4 (b) and has 6.94 for its (c) .
What is the atomic mass?
Match the following
the mass of the atom is found here
nucleus
these are in the nucleus
protons & neutrons
if you change the number of protons you get a different...
element
if you change the number of neutrons you get a different...
mass
an isotope has the same number of protons but a different number of...
neutrons
Which of the following groups of elements are considered perfect in their electronic structure and are inert.
Noble gases
Halogens
Alkali metals
Alkaline earth metals
Which of these elements is a halogen?
Iodine
argon
silver
boron
Which of these elements is an alkaline earth metal?
sodium
sulfur
silver
strontium
Which group does sodium belong to?
Alkali metals
Alkaline Earth Metals
Halogens
Noble Gases
Which group does Chlorine belong to?
Alkali metals
Alkaline Earth Metals
Halogens
Noble Gases
Which group does Barium belong to?
Alkali metals
Alkaline Earth Metals
Halogens
Noble Gases
