Chemistry Sat

Front 1

Define Accuracy:

Back 1

accuracy is how close a value is from its true value. (e.g water may boil at 97 degrees centigrade, but it's true value is 100 degrees centigrade)

Front 2

Define Activation Energy:

Back 2

activation energy is the energy that must be overcome for a chemical reaction to occur. E.g the chemical bond in H2O requires activation energy to break the bonds into H2 and O

Front 3

Define Calorie:

Back 3

calorie is the unit of energy in food, and heat energy. however it is too small to be used, and instead it is replaced by kilocalorie (kilo=1000) However in the SI method, Joule takes its place for heat energy.

1 Calorie = 4.18 Joules

Front 4

Define Celsius

Back 4

The celsius scale is the scale invented by Andor Celsius, which uses the metric system (revolving around 10) and utilizes 100 equally spaced subdivisions markings to indicate from boiling temperature (100) to freezing point (0)

Front 5

Define Chemical Change:

Back 5

a chemical change is the breaking of bonds holding atoms together and the forming of new ones

Front 6

Define Chemical Property:

Back 6

Chemical properties are the properties that cannot be viewed without investigating the substances internal structure.

Front 7

Define Compound:

Back 7

a compound is when two or more atoms are chemically bonded together, due to chemical reactions which form new bonds, unlike mixtures, compounds cannot be easily reversed.

Front 8

Define Density:

Back 8

Density is the ratio of mass per volume.

Mass
Density = Volume

Front 9

Define Element:

Back 9

an element is a substance solely comprised of a single type of atom. elements have chemical and physical properties based on the number of subatomic particles within their atomic structure

Front 10

Define Endothermic Reactions:

Back 10

An endothermic reaction is one where the heat content of the product is greater than the heat content of the reactants. Endothermic reactions have a positive change in heat content. (^H)

Front 11

Define Exothermic Reaction:

Back 11

Exothermic reactions are where the heat content is less than the reactants. the change in heat content is negative (^H)

Front 12

Define Gas:

Back 12

Gas is a state of matter where atoms are uncoordinated and chaotic, assuming the volume of the container. Gas can be highly compressed (due to the lack of atomic density in its structure) and this compression can be measured in PSI (pounds per square inch)

Front 13

Define Heterogeneous:

Back 13

Heterogeneous is an object or system consisting of multiple items having a large number of structural variations.

(Hetero= different)

Front 14

Define homogeneous:

Back 14

Homogeneous is an object or system consisting of multiple identical items

(Homo = same)

Front 15

Define Inertia:

Back 15

Inertia is the amount of force resisting movement. or changes in motion.

Front 16

Define Joule:

Back 16

Joule is the SI unit for measuring heat energy, and the unit for measuring energy in general. Joules like calories are too small to be used and are replaced by Kilojoules.

Front 17

Define Kelvin:

Back 17

the kelvin scale was developed by Lord William Kelvin as a scale utilizing the metric system subdivisions, while utilizing the concept of absolute zero (-273) In this case boiling temperature is considered to be 373 Kelvins, and freezing point is 273, therefore absolute zero is 0.

Front 18

Define Kinetic Energy:

Back 18

Kinetic energy is energy used in motion, it is the extra energy which an object possesses due to its motion.

Front 19

Define Liquid:

Back 19

Liquid is a state of matter where the atoms are orderly arranged, however the atoms are capable of movement, and assume the shape of the container.

Front 20

Define Mass:

Back 20

Mass is the quantity of matter which a substance possesses, and has a unit of weight, based upon the force of gravity acting upon it.

Front 21

Define Meniscus:

Back 21

Meniscus is the curve of liquid in a container, which can make it difficult to judge the true volume of the container.

Front 22

Define Matter:

Back 22

Matter is anyting that has mass and volume (e.g occupies space)

Front 23

Define Mixture:

Back 23

A mixture is two or more substances that are mixed (added) together physically, but not combined chemically

Front 24

Define Physical Change:

Back 24

physical change is any change to the physical properties of the substance. physical changes do not change the chemical properties or the identity of the substance.

Front 25

Define Physical Property:

Back 25

Physical properties are any aspect of an object that can be measured or perceived without changing it's identity

Front 26

Define Potential Energy:

Back 26

Potential energy is energy that is stored and may be converted into other forms of energy

Energy that has potential

Front 27

Define Precision:

Back 27

Precision is the number and the consistency of accurate results.

Front 28

Define Scientific Notation/Standard Form

Back 28

Scientific notation is a way of writing numbers that have too many, or too few zeroes.

Front 29

Define Significant Figures:

Back 29

significant figures the digits of a number whose digits carry meaning contributing to its precision.
Leading and trailing zeroes. (unless there is a zero) where they serve as placeholders.

Spurious digits introduced (e.g by calculations carried out to greater accuracy than of the original data)

Front 30

Define SI Units:

Back 30

SI is a system of measurement revolving around 10, it is the most widely used system of measurement in science and commerce (as it utilizes the metric system)

Front 31

Define Solid:

Back 31

A solid is a state of matter where the atoms are rigidly bound in a cohesive structure and are incapable of movement (although they do vibrate) because of its cohesive structure solids maintain their own shape based on their structure which can be altered or changed based on enough application of heat energy.

Front 32

Define Uncertainty:

Back 32

Uncertainty is the margin of error from human limitation and mistakes. (e.g rounding up or down)

Front 33

What is the law of conservation of energy?

Back 33

the law of the conservation of energy is that energy cannot be created or destroyed in a chemical or physical change.

Front 34

What is the law of conservation of matter?

Back 34

The law of conservation of matter is that matter cannot be created or destroyed, only converted from one form to another

Front 35

What is the law of conservation of mass and energy?

Back 35

The law of conservation of mass and energy is that matter and energy are interchangeable in certain circumstances (e.g in a nuclear reactor)

Energy = Mass x (Velocity of light)squared

E=MC squared

Front 36

What is the law of definite proportion?

Back 36

The law of definite proportion is that a chemical compound always contains exactly the same proportion of elements by mass.