Atomic Theory

John Dalton thought that atoms

• contain molecules.

• cannot be broken down further.

• are all composed of carbon.

• have no mass.

Tags

NGSS.HS-PS1-7

Using improved chemistry equipment in the late 1700s, chemists

observed that mass is neither created nor destroyed in a chemical

reaction. This scientific law is called the law of

• definite proportions.

• gravity.

• conservation of mass.

• conservation of momentum.

Tags

NGSS.HS-PS1-7

In 1808, John Dalton established his atomic theory. Which of the

following is not part of Dalton’s atomic theory?

• All matter is composed of atoms.

• An atom consists of a nucleus and a cloud of electrons.

• Atoms cannot be subdivided, created, or destroyed.

• In chemical reactions, atoms are combined, separated, or rearranged.

Tags

NGSS.HS-PS1-7

Experiments with cathode rays being deflected by a magnetic field

show that cathode rays are composed of particles that are

• magnetic.

• negatively charged.

• positively charged.

• neutral in charge.

Tags

NGSS.HS-PS2-5

Rutherford called the region that deflected alpha particles

• an electron.

• an positron.

• a nucleus.

• a quark.

Tags

NGSS.HS-PS1-8

Cathode rays are composed of particles that are now known as

• positrons.

• neutrons.

• protons.

• electrons.

Except for in the simplest type of hydrogen atom, all nuclei consist of

• protons and electrons.

• neutrons and positrons.

• protons and neutrons.

• electrons and positrons.

Tags

NGSS.HS-PS1-8

Electrons can be found

• inside protons.

• inside neutrons.

• attached to the nucleus.

• moving rapidly outside the nucleus.

What is the charge of a neutron?

• positive

• negative

• neutral

• None of the above

Which is one way that Dalton’s atomic theory has been shown to be incorrect?

• Atoms can change identity in chemical reactions.

• Atoms can be split into subatomic particles.

• Atoms can be destroyed by chemical reactions.

• Some atoms of a particular element are identical to atoms of other elements.

Tags

NGSS.HS-PS1-7