Atoms and molecules

Question 1

what is an atom?

Answer 1

the smallest unit of matter that can combine chemically and cannot be broken down into smaller particles by chemical means.

Question 2

what are atoms made up of?

Answer 2

• protons
• neutrons
• electrons

Question 3

what is a proton?

Answer 3

particles with a positive charge

Question 4

what is a neutron?

Answer 4

particles with no charge

Question 5

what is an electron?

Answer 5

particles with a negative charge

Question 6

what does a proton and neutron formulate?

Answer 6

the nucleus of all atoms except hydrogen

Question 7

what does an electron do?

Answer 7

orbit the nucleus of an atom

Question 8

what are elements?

Answer 8

substances that cannot be broken down into other substances. they are made of a single type of atom. Each element has a chemical symbol.

Question 9

what are compounds?

Answer 9

substances formed of 2 or more elements chemically combined in a definite proportion. compounds have properties that differ from the properties of the elements that they contain. Compounds are represented by chemical formulas

Question 10

what are mixtures?

Answer 10

physical combinations of 2 or are substances that keep their own property

Question 11

when elements combine to form molecules or ionic compounds they are held together by what?

Answer 11

bonds

Question 12

what are the 2 main types of bonds

Answer 12

• covalent

- covalent bond

Question 13

what is a covalent?

Answer 13

atoms that scare a pair of electrons

Question 14

what is a covalent bond?

Answer 14

atoms share a pair of electrons, each atom contributing one electron

Question 15

what is ionic bonds?

Answer 15

when atoms gain or lose electrons to become ions, and the attraction between positively and negatively charged ions hold the compounds together