Unit 2

Question 1

Definition of matter

Answer 1

Matter is anything that takes up space and can be weighed. In other words, matter has volume and mass.

Question 2

Definition of physical property

Answer 2

The physical properties of a substance are the inherent characteristics of the substance, which result in no change in the composition of the substance when we measure or study those properties. Such properties include color, odor, physical state, density, solubility, melting point, and boiling point.

Question 3

Definition of chemical property

Answer 3

The chemical properties of a given substance indicate how that substance reacts with other substances. For example, when we say that sodium is a grayish white, soft low-density metal, we are describing some of sodium’s physical properties. When we say that sodium metal reacts with chlorine gas to form sodium chloride, it’s a chemical property.

Question 4

Definition of density

Answer 4

How much stuff in a certain amount of space. Ratio that compared the mass of an object to its volume

Question 5

Def of Physical change

Answer 5

A physical change for a substance does not alter the identity or composition of the substance; such a change typically represents a change in physical state, shape or size. a substance results in the substance being converted into another substance or substances. For example, when we heat a piece of sodium metal in a sealed tube in a burner flame, the sodium melts and then vaporized: the liquid and gas are still sodium, however, only physical changes have occurred.

Question 6

Def of chemical change

Answer 6

A chemical change for a substance results in the substance being converted into another substance or substances. But if we heat a piece of sodium in an open flame, the sodium reacts with oxygen in the air and is converted to a mixture of sodium oxides. The pure elemental substance sodium is converted into compounds and has undergone a chemical change.

Question 7

Law of conservation of mass

Answer 7

Mass is neither created nor destroyed in any physical or chemical process
The total mass before a reaction or change must equal the total mass after the reaction or change

Question 8

Chemical symbol

Answer 8

Carbon=C
Hydrogen=H

Question 9

Reactants

Answer 9

What’s used in the experiment. Front half if equation

Question 10

Products

Answer 10

What you end up with. End of equation

Question 11

Chemical reaction

Answer 11

Produces a change in properties

Question 12

Chemical formula

Answer 12

H20 Or CO2
How many parts of each element you have. H2O has a 2:1 ratio of 2 hydrogen atoms and 1 oxygen

Question 13

Precipitate

Answer 13

Formation of a solid in a solution

Question 14

Filtrate

Answer 14

Material, usually liquid, that has passed through a filter

Question 15

Residue

Answer 15

Material remaining after a distillation or evaporation

Question 16

Solution

Answer 16

Also known as a homogenous mixture. A uniform mixture made up of two or more substances

Question 17

Solvent

Answer 17

Substance that dissolves a solute (water in saltwater)

Question 18

Solute

Answer 18

Substance BEING dissolved in a solution (salt in saltwater)

Question 19

Data

Answer 19

Observations that we have organized into a table, graph, or chart 

Question 20

Scientific law

Answer 20

A summary of many experimental results and observations, a law that tells how things work

Question 21

Theory

Answer 21

An explanation for some phenomenon that is based on observation, experimentation and reasoning 

Question 22

Endothermic

Answer 22

USES heat energy like ice packs

Question 23

Exothermic

Answer 23

GIVES OFF heat energy, like hand warmers

Question 24

Substance

Answer 24

Any material that possesses physical properties is called a substance. Classification of matter made up of all the same kind of atom, all bonded chemically. Pure substance has a definite and constant composition like salt or sugar. Composition doesn’t vary.

Question 25

Element definition

Answer 25

An element cannot be broken down into simpler substances by chemical means. There are 118. Composed of a single kind of atom.

Question 26

Compound definition

Answer 26

Made of 2 or more elements in a specific ratio. Compounds CAN be broken down into the component elements by chemical changes. In general, the properties of a compound are very different from the properties of its constituent elements. For example, the properties of water are altogether different from the properties of the elements (hydrogen gas and oxygen gas) that make it up.

Question 27

Mixture

Answer 27

Physical combinations that have no definite or constant composition. Varies on who prepared the mixture. is a compound made up of two or more chemical components that are not chemically linked.

Question 28

Homogenous mixture

Answer 28

Homogeneous (same) means there are no variations in composition in different areas of the sample of that mixture. Also known as solutions. Shampoo, window cleaner, rubbing alcohol

Question 29

Heterogenous

Answer 29

Moisture that varies from position to position within the same sample. Like sugar and sand. Doesn’t have the same comp throughout the jar.

Question 30

Alloy

Answer 30

A mixture composed of two or more elements, at least one of which is a metal. Brass is an alloy of copper and zinc

Question 31

Distillation

Answer 31

Consider a solution of 3 different liquids. When you start to boil the mixture, the liquid with the lowest boiling point will boil and then condense into another flask. The temperature begins to rise again until reaches the boiling point of the second liquid. Liquid number two boils and condenses. Then the same happens for the third and last liquid in the mixture.

process involving the conversion of a liquid into vapour that is subsequently condensed back to liquid form

Question 32

Filtration

Answer 32

Consider a mixture of salt and sand. Salt is soluble in water; sand is not. The mixture is added to water and stirred to dissolve the salt, and is then filtered. The salt solution passes through the filter; the same remains on the filter. The water can then be evaporated from the salt.

Liquid drains through filter paper funnel

the process in which solid particles in a liquid or gaseous fluid are removed by the use of a filter medium that permits the fluid to pass through but retains the solid particles.

Question 33

Chromatography

Answer 33

Chromatography is a process for separating components of a mixture. To get the process started, the mixture is dissolved in a substance called the mobile phase, which carries it through a second substance called the stationary phase.
Ink smears on paper

Question 34

Observation

Answer 34

Any information that is gathered with the senses.

Question 35

Inference

Answer 35

Educated guess based OFF your five senses

Question 36

TEN INDICATORS of chemical change

Answer 36

1. Production of light
2. Production of heat
3. Produces bubbles (gas)
4. Color change *
5. Change in odor
6. Formation of precipitate (solid)
7. Gets cold without a coolant
8. Gives off smoke
9. Change in texture*
10. Change in appearance *
    * don’t rely on just this