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Atomic Theory Practice MCQ

Total questions: 17

Worksheet time: 9mins

Name
Class
Date
1.

Dalton incorporated the law of conservation of mass into his atomic theory by asserting that...

a)

matter is composed of atoms.

b)

atoms can be destroyed in chemical reactions.

c)

atoms are indivisible.

2.

Dalton's atomic theory agrees with modern atomic theory except for the statement that

a)

atoms are not divided in chemical reactions.

b)

all atoms of the same element have the same mass.

c)

atoms of the same element are chemically alike.

3.

Which of the following statements is true according to modern atomic theory?

a)

Atoms can never combine with any other atoms.

b)

Atoms may be divided in ordinary chemical reactions.

c)

Atoms of the same element may have different masses.

4.

Whose series of experiments identified the nucleus of the atom?

a)

Bohr

b)

Rutherford

c)

Thomson

5.

In Rutherford's experiments, most of the particles

a)

were absorbed by the foil.

b)

passed through the foil.

c)

combined with the foil.

6.

Because a few alpha particles bounced back from the foil, Rutherford concluded that they were

a)

striking electrons.

b)

magnetic.

c)

repelled by densely packed regions of positive charge.

7.

An atom is electrically neutral because

a)

the numbers of protons and neutrons are equal.

b)

the numbers of protons and electrons are equal.

c)

neutrons balance the protons and electrons.

8.

Isotopes are atoms of the same element that have different

a)

numbers of protons.

b)

masses.

c)

numbers of electrons.

9.

The atomic mass of an element listed in the periodic table is the

a)

average atomic mass.

b)

relative atomic mass of the most abundant radioactive isotope.

c)

mass number of the least abundant isotope.

10.

Max Planck proposed that a hot object radiated energy in small, specific amounts called

a)

waves.

b)

quanta.

c)

electrons.

11.

According to the Bohr model of the atom, the single electron of a hydrogen atom circles the nucleus

a)

in specific, allowed orbits.

b)

in one fixed orbit at all times.

c)

at any of an infinite number of distances, depending on its energy.

12.

According to Bohr, electrons cannot reside at ____ in the figure below.

a)

b

b)

c

c)

d

13.

The region outside the nucleus where an electron can most probably be found is the

a)

electron cloud.

b)

electron configuration.

c)

allowable orbit.

14.

A three-dimensional region around a nucleus where an electron may be found is called a(n)

a)

atomic orbital.

b)

electron path.

c)

spectral line.

15.

According to the quantum theory of an atom, in an orbital

a)

electrons travel around the nucleus on paths of specific radii.

b)

an electron's position cannot be known precisely.

c)

electrons cannot be found.

16.

Which of the following scientists proposed an atomic theory of matter based upon the atom as a "plum pudding"?

a)

Dalton

b)

Thomson

c)

Bohr

17.

The observation that most alpha particles passed straight through an atom of gold lead Rutherford to conclude

a)

that the atom was mostly empty space.

b)

that the atom contained a large nucleus.

c)

that the atom had a positively charged nucleus.