Atoms

The smallest unit of an element is __________

• matter

• a cell

• a proton

• an atom

What is the center of an atom called?

• neutron

• nucleus

• proton

• electron

What part of an atom has a positive charge?

• protons

• electrons

• neutrons

• atoms

How many elements are there in the world?

• 116

• infinite

• 250

• 100

What two things are found in the nucleus of an atom?

• protons and neutrons

• protons and electrons

• electrons and neutrons

• protons only

What have a negative charge?

• neutrons

• protons

• electrons

• atoms

What have a neutral charge (or no charge)?

• protons

• electrons

• neutrons

• atoms

What part of the atom is the most dense, and where most of the mass is found?

• protons

• nucleus

• neutrons

• electrons

An atom is made up of mostly ___________________________

• electrons

• protons

• neutrons

• empty space

A substance that cannot be broken down into anything simpler is _____________________.

• an element

• a compound

• atoms

• matter