Radioactivity — Unit test Answers

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21
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Where are alkaline earth metals found on the periodic table?

A
Group 1
B
Group 2
C
Groups 3–12
D
Group 17
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Which have different numbers of electrons?

A
different ions of an element
B
different isotopes of an element
C
the nucleus of an element
D
each of the atoms of an element
23

What best describes the states of nonmetals when they are at room temperature?

A
Most nonmetals are gaseous, but some are liquid or solid.
B
All nonmetals are gaseous unless they bond with a metal.
C
Most nonmetals are solids, but some are gaseous or liquid.
D
All nonmetals are solid unless they bond with a metal.
24

What is an atomic nucleus?

A
the outer part of an atom in which electrons move
B
the outer part of an atom in which neutrons move
C
the central part of an atom, composed of protons and neutrons
D
the central part of an atom, composed of protons and electrons
25

Which metal is most likely to form more than one kind of positively charged ion?

A
sodium (Na)
B
barium (Ba)
C
nickel (Ni)
D
magnesium (Mg)
26

Which scientist believed that the probable, not exact, location of the electrons of an atom can be determined by using mathematics?

A
Rutherford
B
Bohr
C
Dalton
D
Schrödinger
27

Particle A has very little mass in comparison to Particle B. Both particles are in the same atom. Which is the best conclusion about Particles A and B?

A
They have the same charge.
B
They are located in the nucleus together.
C
Particle A has a positive charge, and Particle B is neutral.
D
Particle A orbits the nucleus, and Particle B is located in the nucleus.
28

How does Rutherford’s model of the atom compare with Thomson’s model?

A
They both describe atoms as small, indivisible spheres.
B
They both describe electrons as moving around the nucleus.
C
They both describe electrons as being surrounded by the positive matter.
D
They both describe atoms as being made up of positive and negative matter.
29

Rutherford used positively charged particles to investigate the structure of the atom. The results surprised him, and he developed the atomic model shown below.

Question illustration
A
A few positive particles bounced back because they bounced off of the net formed by the ovals.
B
A few positive particles bounced back because they were pushed away from the positive center.
C
Most positive particles passed through because of the empty space between the outer edge and the center.
D
Most positive particles passed through because they were attracted by the small particles moving around the center.
30

Scientists have changed the model of the atom as they have gathered new evidence. One of the atomic models is shown below.

Question illustration
A
A few of the positive particles aimed at a gold foil seemed to bounce back off of the thin metallic foil.
B
Experiments with water vapor showed that elements combine in specific proportions.
C
Equations were used to identify regions around the nucleus where electrons would likely be.
D
Cathode rays were bent in the same way whenever a magnet was brought near them.
31

Students are completing a table about a particular subatomic particle that helps make up an atom.What best explains how they should complete the table?

Question illustration
A
with “Inside the nucleus,” because the particle is a proton
B
with “Inside the nucleus,” because the particle is a neutron
C
with “Outside the nucleus,” because the particle is a proton
D
with “Outside the nucleus,” because the particle is an electron

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