Science 8 Ch. 11

All substances are made of atoms

The number of protons in the nucleus is the ______________ number.

Isotopes always have the _______ number of protons, but different neutrons.

mass of an atom in A.M.U. (Atomic Mass Units)

Objects are pulled towards one another during ____________ force.

Of all the subatomic particles the one with the least mass is the electron.

Dalton, Democritus, Thomson, Rutherford, and Bohr contributed to the modern ___________ Theory.

Thomson discovered negatively charged particles called ____________.

The ¨plum¨ in the plum pudding model represents the ________________.

Elements are a mixture of two or more _______________.

According to Ruthherford, what is in the center of an atom?

Describes the mass of an atomic in SI units

Adding protons and neutrons gives you the ______________ number.

An electron has a _____________ charge.

All ____________ is made up of atoms

The current atomic theory includes the _______________ model.

An element divided into the smallest particle and still be the same substance is known as an _.

An _____________ force holds electrons in place around the nucleus.

¨Not able to be divided" is the meaning of what word in Greek?

Isotopes always have the same number of ______________.

A ______________ has a positive charge.

A __________ force keeps the protons together in the nucleus