Unit 3 Part 1

An ____________ is the smallest piece of an element that still represents that element.

• atom

• molecule

• mixture

• compound

Tags

NGSS.MS-PS1-1

Thomson's atomic model stated that an atom is a positively charged sphere with __________________ throughout it.

• protons

• neutrons

• electrons

• quarks

Tags

NGSS.MS-PS1-1

Rutherford's atomic model proposed that most of an atom's mass and ______________________charge is concentrated in the _________________ of an atom.

• positive, center

• negative, center

• neutral, center

• positive, outside

Tags

NGSS.MS-PS1-1

Bohr's atomic model proposed that __________________ move in circular orbits, or energy levels

• electrons

• protons

• neutrons

• quarks

Tags

NGSS.MS-PS1-1

In modern atomic theory, electrons form an electron _____________, which is the area around the nucleus where electrons are located.

• cloud

• square

• circle

• box

Most of the mass of an atom is in the ___________________.

• nucleus

• cloud

• shells

• energy levels

Tags

NGSS.MS-PS1-1

The number of protons (and electrons) in an atom is the atomic ____________________.

• number

• mass

• level

• group

Tags

NGSS.MS-PS1-1

Elements that spontaneously emit radiation are called _______________________.

• radioactive

• nuclear decay

• electromagnetic

• convection

Tags

NGSS.HS-PS1-8

A __________________ ion has lost electrons and a __________________ ion has gained electrons.

• positive, negative

• negative, positive

• positive, neutral

• negative, neutral

Which scientist proposed that matter is made of small, indivisible objects called atoms?

• Democritus

• Aristotle

• Rutherford

• Chadwick

Tags

NGSS.MS-PS1-1