Chemistry - Atoms, Molecules and Compounds

Question 1

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

Accepted Answer

an element

Question 2

__________________ have a neutral charge.

Accepted Answer

neutrons

Question 3

A substance made up of two or more elements is __________________.

Accepted Answer

a compound

Question 4

The densest part of an atom where most of its mass is located is the __________________.

Accepted Answer

nucleus

Question 5

An atom is made mostly of __________________.

Accepted Answer

empty space

Question 6

__________________ has a negative charge.

Accepted Answer

electrons

Question 7

An example of a compound is __________________.

Accepted Answer

water

Question 8

The person known as the "Inventor of the Periodic Table" in 1869 is a Russian scientist named

Accepted Answer

Dmitri Mendeleev

Question 9

Another name for an atom or molecule WITH a charge, as it either lost or gained an electron.

Accepted Answer

Ion

Question 10

An example of a compound is __________________.

Accepted Answer

water

Question 11

The smallest unit of an element is __________________.

Accepted Answer

an atom

Question 12

The ____________________ is the center of an atom.

Accepted Answer

nucleus

Question 13

__________________ have a positive charge.

Accepted Answer

protons

Question 14

There are __________________ elements in the world.

Accepted Answer

118

Question 15

The nucleus is made up of __________________.

Accepted Answer

neutrons & protons

Questions 15