Chapter 7 science

Question 1

Matter

Answer 1

Anything that has mass and takes up space. (Physical objects, earth, air, fire, water, etc…) (sound and light are not matter)

Question 2

Atoms

Answer 2

Small particle – building block of matter

At the center of the atom is a nucleus. A nucleus is made of protons with a + charge and Neutrons with a neutral charge.
Electrons ( - charge) move quickly around the nucleus in an electron cloud.

The properties of an atom are based on the number of protons in its nucleus. This determines the properties of the matter.

Question 3

Substances

Answer 3

Matter with a composition that is always the same (same combination of atoms)

made of compounds and elements

Question 4

Elements

Answer 4

A substance that consists of just one type of atom (aluminum, hydrogen, oxygen)
118 known elements and 118 types of atoms

Each type of atom contains a different number of protons in its nucleus. (aluminum has 13)

Question 5

Compounds

Answer 5

A type of substance containing atoms of two or more different elements.
Carbon dioxide is a compound. its atoms are made of carbon and oxygen.
chemically bonded together (CO2 , H2O

Question 6

chemical formulas

Answer 6

a combination of symbols and numbers used to represent a compound.

Question 7

Mixtures:

Answer 7

Matter that can vary in composition

Question 8

A Heterogeneous Mixture is a mixture in which individual substances are not evenly mixed (like a salad)

Answer 8

is a mixture in which individual substances are not evenly mixed (like a salad)

Question 9

Homogeneous Mixture (a solution) is mixture in which the substances are evenly mixed would be (like orange juice)

Answer 9

is mixture in which the substances are evenly mixed would be (like orange juice)

Question 10

Solvent:

Solute:

Answer 10

The majority of the mixture (water usually)

The other substances in a solution (sugar, orange pulp, etc…)

Question 11

Compounds vs Solutions:

Answer 11

A compound is a single substance or just the solvent

Solutions are two or more substances mixed together.

Question 12

A physical property:

Answer 12

is a characteristic of matter that you can observe or measure without changing the identity of the matter.

Question 13

The arrangement of atoms determines whether matter is a substance or a mixture

The arrangement of atoms determines the properties of different types of matter.

When substances mix together and form mixtures, the properties of the substances that made up the mixture are still present.

Question 14

States of matter examples

Answer 14

Aluminum is an element, and a solid at room temperature.

water is a compound, and a liquid at room temperature.

air is a mixture, and a gas at room temperature

Question 15

What determines the state of matter?

Answer 15

It depends of how close together the particles are and how fast they are moving

Atoms that make up matter are constantly moving and are attracted to each other.

Question 16

Mass

Answer 16

Mass is the amount of matter in an object.
Size dependent

Mass is not the same as weight, mass is the amount of matter while weight is the pull of gravity

Mass does not change with location like weight

Question 17

Volume

Answer 17

Volume is the amount of space something takes up.
size dependent

Question 18

Melting point:

Answer 18

the temp at which substances change from solid liquid

Question 19

Boiling point

Answer 19

: the temp at which substances change from liquid to gas
boiling point for water is 100 deg celsius at sea level

Question 20

Density

Answer 20

Density is mass per unit volume of a substance
a bowling ball is denser than a foam ball

Question 21

Electrical conductivity

Answer 21

is the ability of matter to conduct, or carry along, an electric current.
(copper)

Question 22

Thermal conductivity

Answer 22

is the ability of matter to conduct thermal energy.
(metal)

Question 23

Solubility

Answer 23

the ability of 1 substance to dissolve into another.
(kool aid powder is soluble) sand is not

Question 24

Separating mixtures

Answer 24

When substances form a mixture, the properties of the substances stay the same.

Question 25

Mixture vs compound

Answer 25

parts of a mixture can often be separated by physical properties.

Compounds can not be separated into elements by physical properties.