Chem

According to Dalton's atomic theory, atoms...

• of different elements combine in simple whole-number ratios to form compounds.

• can be divided into protons, neutrons, and electrons.

• of all elements are identical in size and mass.

• can be destroyed in chemical reactions.

Because most particles fired at metal foil passed straight through, Rutherford concluded that

• atoms were mostly empty space.

• atoms contained no charged particles.

• electrons formed the nucleus.

• atoms were indivisible.

Rutherford fired positively charged particles at metal foil and concluded that most of the mass of an atom was

• in the electrons.

• concentrated in the nucleus.

• evenly spread throughout the atom.

• in rings around the atom.

A positively charged particle with mass 1.673 ´ 10^–24 g is a(n)

• proton

• neutron

• electron

• quark

Which part of an atom has a mass approximately equal to about 1/2000 of the mass of a common hydrogen atom?

• nucleus

• electron

• proton

• electron cloud

The mass of a neutron is

• about the same as that of a proton.

• about the same as that of an electron.

• double that of a proton.

• double that of an electron.

The nucleus of most atoms is composed of

• tightly packed protons.

• tightly packed neutrons.

• tightly packed protons and neutrons.

• loosely connected protons and electrons.

Most of the volume of an atom is occupied by the

• nucleus.

• nuclides.

• electron cloud.

• protons.

The charge on the electron cloud

• prevents compounds from forming.

• balances the charge on the nucleus.

• attracts electron clouds in other atoms to form compounds.

• does not exist.

The smallest unit of an element that can exist either alone or in combination with other such particles of the same or different elements is the

• electron

• proton

• neutron

• atom