Chapter 19: Properties of Atoms and the Periodic Table

The scientist who proposed the idea that atoms make up all substances was

Which is not found in the nucleus of an atom?

Of the three particles, which one is the smallest?

The elements in Group 1 have ___ electrons.

Elements that are in the same group have the same number of _____ in their outer energy levels.

The unit of measurement used for atomic particles is the

The weighted average mass of the mixture of an element's isotopes is called the

This particle is found in the nucleus with protons.

The sum of the number of protons and neutrons in an atom is called the

The area around the nucleus where electrons are found is the

The scientist who offered proof that atoms exist was

Particles with a positive charge are called

The vertical columns in the periodic table are called

Atomic number is equal to the number of

Protons and neutrons are made up of smaller particles called

In this table, elements are arranged by changes in physical and chemical properties.

The number of this particle is equal to the number of protons.

An element is matter that is composed of one type of

Particles that are neutral and do not have a charge are

This particle is found orbiting the nucleus.

Particles that have a negative charge are called

The elements in Group 18, the noble gases, have _____ electrons.

The elements in Group 17, the halogens, have ____ electrons in their outer energy levels.

A complete and stable outer energy level will contain _______ electrons.

The number of protons in an atom is equal to a number called the

The rows in the periodic table are called

A ____ uses the symbol of the element and dots to represent electrons.

Atoms of the same element that have different numbers of neutrons are called

The small, positively charged center of the atom is called the

The number of this particle determines the element.