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WorksheetsUnit 2 Practice Test
Total questions: 25
Worksheet time: 28mins
The atomic number of an element indicates which quantity?
the number of neutrons in the atom
the number of protons in the atom
the sum of the neutrons and protons in the atom
the sum of the protons and electrons in the atom
Rutherford’s gold foil experiment used positively charged alpha particles fired at thin gold foil. Which conclusion followed from the observed scattering?
The nucleus is negatively charged.
The atom is a dense solid and is indivisible.
The mass is conserved when atoms react chemically.
The nucleus is very small and the atom is mostly empty space.
Which of the following ideas was proposed by Niels Bohr?
Electrons occupy specific energy levels within an atom.
The nucleus of an atom contains neutrons as well as protons.
An atom is a solid sphere that cannot be separated into smaller parts.
An atom consists of negative charges embedded in a positively charged sphere.
A positively charged ion always has more of which particle?
protons than neutrons
neutrons than protons
protons than electrons
electrons than protons
Zirconium (Zr) has atomic number 40 and a mass number of 91. How many protons, neutrons, and electrons are present in a neutral atom of Zr?
40 protons, 51 neutrons, 40 electrons
91 protons, 40 neutrons, 51 electrons
51 protons, 40 neutrons, 91 electrons
40 protons, 91 neutrons, 40 electrons
Which statement best describes a difference between nuclear fission and nuclear fusion reactions?
Nuclei split during fission and combine during fusion.
Fission forms heavier elements, and fusion forms lighter elements.
Fission generates potential energy, and fusion generates kinetic energy.
Nuclei gain electrons during fission and release electrons during fusion.
Which statement best explains why neon-22 is considered an isotope of neon?
Neon-22 has more protons than other neon atoms.
Neon-22 has a different number of neutrons compared to other neon atoms.
Neon-22 has a different number of electrons than other neon atoms.
Neon-22 has the same mass number as other neon atoms.
19.5% of all isotopes of an element have a mass of 80.91 amu, 53.2% have a mass of 79.90 amu, and 27.3% have a mass of 81.00 amu. What is the average atomic mass of this element?
80.30 amu
80.27 amu
79.95 amu
80.10 amu
What is the mass number of an element defined as?
Number of protons
Number of neutrons
Number of neutrons and protons
Number of protons and electrons
All atoms of the same element have the same ____________.
number of neutrons
number of protons
mass number
mass
What name did Democritus give to the smallest, indivisible pieces of matter in his theory around 400 BC?
molecules
neutrons
atomos
ions
Which discovery about the atom is attributed to J.J. Thomson?
Atoms are indivisible
Atoms contain electrons
Atoms are made only of positive charges
Atoms have no internal structure
While nuclear power can generate electricity efficiently, it also has drawbacks. Which of the following is a disadvantage of using nuclear power?
Nuclear power plants reduce air pollution.
Nuclear power plants require less fuel than fossil fuel plants.
Nuclear power produces radioactive waste that is difficult to manage.
Nuclear power plants can be built in many locations.
What do the horizontal rows in the periodic table represent?
Elements with the same number of electron shells.
Elements with similar chemical properties.
Elements listed in alphabetical order.
Elements discovered in the same year.
Why is the periodic table called "periodic"?
Because it lists all known substances.
Because it is organized in a grid format.
Because the chemical properties of elements show a repeating pattern.
Because each element is unique from the others.
Which two elements on the periodic table are in the same period?
Fe and Co
F and I
K and Rn
Se and Xe
In early versions of the periodic table, elements were arranged based upon atomic mass. The elements on the modern periodic table are now arranged in order of what property?
atomic number
date of discovery
number of neutrons
reactivity with hydrogen
An element has atomic number 38. Based on the periodic table classification, it is a:
metal
metalloid
nonmetal
synthetic element
Which statement about the periodic table is true?
There are more nonmetals than metals.
The middle section contains the transition metals.
The elements at the far left of the table are nonmetals.
Elements are arranged by increasing atomic mass.
When radioactive elements like uranium break down, what do they typically produce?
Heavier elements
New elements
Organic matter
Energy only
What typically happens to the stability of a nucleus when carbon-14 undergoes radioactive decay?
The nucleus becomes less stable.
The nucleus becomes more stable.
The number of protons decreases.
The number of neutrons increases.
Thallium-208 (208/81 Tl) decays directly to lead-208 (208/82 Pb). Which particle is released during this decay?
alpha particle
beta particle
neutron
proton
According to the periodic table, which of the following has 20 protons and 18 electrons?
a calcium ion with a 2+ charge
a potassium ion with a 1+ charge
a neutral calcium atom
a neutral potassium atom
2760Co = ___ + -10e
85209At = ___ + 24He
