Chemistry- part 1

Question 1

What is Chemistry?

Answer 1

Chemistry is the study of matter and the way it behaves under different conditions.

Question 2

What is matter?

Answer 2

Matter is anything that has mass and occupies space.

Question 3

What are the 3 states of matter?

Answer 3

• solid
• liquid
• gas

Question 4

What is diffusion ?

Answer 4

Diffusion is the spreading out of particles of a substance from a region of high concentration to a region of low concentration.

Question 5

Gas to Solid is called___.

Answer 5

Gas to Solid is called -re-sublimation or deposition-

Question 6

Solid to Gas is called_____.

Answer 6

Solid to Gas is called sublimation.

Question 7

What is a physical change?

Answer 7

A physical change is one in which no new substance is formed.

Question 8

What is a chemical change?

Answer 8

A chemical change is one in which one or more new substances are formed.

Question 9

What is a physical property?

Give 3 examples.

Answer 9

A physical property of a substance is one that gives the characteristics of the substance. (eg: shape, odor, texture, melting point, boiling point)

Question 10

What is a chemical property?

Answer 10

A chemical property of a substance is one that describes how a substance behaves during a chemical reaction.

Question 11

What is an element?

Answer 11

An element is a substance that consists of one kind of atom.

Question 12

What is a mixture?

Answer 12

A mixture is any composition of 2 or more substances that are NOT chemically combined together.

Question 13

What is a compound?

Answer 13

A compound is a substance that contains two or more elements that are chemically combined.

Question 14

What is a compound?

Answer 14

A compound is a substance that contains two or more elements that are chemically combined.

Question 15

What is the difference between a reactants and a products?

Answer 15

Reactants are things we start within a reaction.

Products are things that are made in a reaction.

Question 16

What is the Chemical Formula for sodium chloride?

Answer 16

NaCl

Question 17

What is a solution?

Answer 17

A solution is a mixture that is formed when a solid dissolves in a liquid.

Question 18

What is a solute and what is a solvent?

Answer 18

• The solute is the substance that is being dissolved.

* The solvents is the substance that is doing the dissolving.

Question 19

What is an Atom?

Answer 19

All matter is made up of tiny particles called atoms.

Question 20

A group of atoms that a joined together is called a___-.

Answer 20

A group of atoms that a joined together is called a - molecule-

Question 21

Which particles in an atom is negatively, positively or neutrally charged?

Answer 21

• Protons- positive
• Neutrons- neutral
• Electrons- negative

Question 22

The nucleus is a solid mass in the center of the atom. It is made up 2 particles. Which 2 particles is the nucleus made of?

Answer 22

• Protons

* Neutrons

Question 23

How many Elements are there?

Answer 23

118

Question 24

Name 5 of the noble gasses.

Answer 24

*He- Helium
*Ne- Neon
*Ar- Argon
*Kr- Krypton
Xe- Xenon

Question 25

What is filtration?

Answer 25

A process used to separate a liquid from a solid.

Question 26

What is decantation?

Answer 26

A process that involves pouring off a liquid from a solid that is usually heavy and at the bottom of the vessel.

Question 27

What is centrifugation?

Answer 27

A process is used to separate solid from a liquid if the solid is very fine and will block the holes in the filter paper.

Question 28

What is evaporation?

Answer 28

A process used to separate a solid from a solution.

Question 29

What is simple distillation?

Answer 29

A process used to separate a solute from a solvents in a solution.

Question 30

What is fractional distillation?

Answer 30

A process used to separate to miscible objects, completely.

Question 31

What is a separating funnel used for?

Answer 31

A separating funnel is used to separate two immiscible liquids.

Question 32

What is chromatography?

Answer 32

A process used to separate colored substances present in a solution.

Question 33

What is sublimation?

Answer 33

A process used to separate a solid which sublimes from one or more solids that do not sublime.

Question 34

What is magnetism?

Answer 34

A process used to separate a magnetic solid from a mixture of solids.

Question 35

What is air?

Answer 35

Air is a mixture.

Question 36

What is pollution?

Answer 36

Pollution is the contamination of the environment by substances that are harmful to life.

Question 37

``` What percentage is air made up of: Nitrogen- Oxygen- Argon- Carbon dioxide- ```

Answer 37

Nitrogen- 78% Oxygen- 21% Argon- 0.93% Carbon dioxide- 0.03%

Question 38

What is air pressure?

Answer 38

Air pressure is the weight of the air above a given place on earth.

Question 39

What is the formula for respiration?

Answer 39

6 O2 + C6H12O6 -----> 6 CO2 + 6 H2O

Question 40

What is the formula for photosynthesis?

Answer 40

6 CO2 + 6 H2O ---> C6H12O6 + 6 O2

Question 41

What is the atmosphere?

Answer 41

The atmosphere is a blanket of protective gases that covers the earth's surface, providing insulation against extreme temperatures.

Question 42

What are the 5 layers of the earth in order?

Answer 42

* Troposphere - 1st layer * Stratosphere- 2nd layer * Mesosphere- 3rd layer * Ionosphere- 4th layer * Exosphere- 5th layer

Question 43

Which layer of the atmosphere contains the ozone?

Answer 43

Stratosphere

Question 44

List 4 uses of Oxygen.

Answer 44

* Welding and cutting metals * Burning of rocket fuels * Removal of impurities from molting metal * As a respiratory aid

Question 45

List 5 uses of carbon dioxide.

Answer 45

* Used to make fizzy drinks * The solid form (dry ice) is used as a refrigerant * In fire extinguishers * It is used in baking * It is used by green plants for photosynthesis