Atomic Theory and Structure

What is the sum of an atom's protons and neutrons called?

• atom

• atomic theory

• atomic mass

• atomic number

Tags

NGSS.HS-PS1-8

The _____ is based on the number of protons in the nucleus of the atom.

• atomic structure

• periodic table of the elements

• atomic number

• atomic mass

Which scientist developed the atomic theory?

• JJ Thomson

• Ernest Rutherford

• John Dalton

• James Chadwick

He developed the planetary model of the atom.

• Rutherford

• Bohr

• Chadwick

• Dalton

What did Thomson discover?

• electron

• proton

• neutron

• electron cloud

James Chadwick discovered the ________.

• proton

• neutron

• electron

• nucleus

Tags

NGSS.HS-PS1-8

He claimed that matter was made of small, hard particles that he called “atomos.”

• Democritis

• Dalton

• Moseley

• Einstein

Believed that atoms of the same element are identical to each other

• Bohr

• Rutherford

• Dalton

• Thomson

The best images of atoms look fuzzy because of their 

• small size 

• constant motion

• fast-moving electrons

• thunder and lightning

The atom's mass is determined by the number of 

• protons and neutrons

• protons and electrons

• neutrons and electrons

Tags

NGSS.HS-PS1-7