Atomic Theory Practice MCQ

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

• matter is composed of atoms.

• atoms can be destroyed in chemical reactions.

• atoms are indivisible.

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

• Atoms can never combine with any other atoms.

• Atoms may be divided in ordinary chemical reactions.

• Atoms of the same element may have different masses.

Whose series of experiments identified the nucleus of the atom?

• Bohr

• Rutherford

• Thomson

In Rutherford's experiments, most of the particles

• were absorbed by the foil.

• passed through the foil.

• combined with the foil.

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

• striking electrons.

• magnetic.

• repelled by densely packed regions of positive charge.

An atom is electrically neutral because

• the numbers of protons and neutrons are equal.

• the numbers of protons and electrons are equal.

• neutrons balance the protons and electrons.

Tags

NGSS.HS-PS1-7

Isotopes are atoms of the same element that have different

• numbers of protons.

• masses.

• numbers of electrons.

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

• average atomic mass.

• relative atomic mass of the most abundant radioactive isotope.

• mass number of the least abundant isotope.

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

• electron cloud.

• electron configuration.

• allowable orbit.

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

• that the atom was mostly empty space.

• that the atom contained a large nucleus.

• that the atom had a positively charged nucleus.