Chapter 1-3 science test

What is science?

Observing, Studying, and experimenting to find the nature of things.

What are the main branches of science?

Biological

Physical

Earth Science

Scientific Law

describes a process in nature that can be tested

Scientific Theory

Explanation of a natural process

Experimental group

identical to control group except 1 factor

Control group

provides a normal standard against which you can compare the results

Dependent variable

variable that is measured

Independent variable

manipulated variable

Si Base Untis

7 base units

Mass

length

time

temperature

amount of substance

electric current

luminous intensity

Metric prefixes

Kilo

hecto

deca

Unit

deci

centi

milli

Scientific notation

used to represent a very large number or small number 7uy7

Significant figures

Show us how many figures are known for sure

Chemistry

matter and its changes

matter

Anything hat has mass and take up space

Composition of Matter

Atoms

Compounds

Molecules

Elements

chemical formula

A combination of chemical symbols and numbers to represent a substance

Pure substances

matter that cannot be separated into other kinds of Matter by any physical process

mixtures

material that can be separated by physical means into 2 or more substances

Homogenous mixtures

Evenly mixed throughout

heterogenous Mixtures

Combination of 2 or more substances that are not evenly mixed

Physically properties

Characteristics of a substance that doesn’t involve a chemical change

chemical properties

A characteristic of a substance that indicates it can change chemically 

Physical change

change in form

Chemical change

change in which one or more kinds of Matter are transformed into a new kind of Matter

Density

ratio of mass to volume of a substance

Law of conservation of mass

matter is not created or destroyed during a chemical change

States of matter

Solid (definite volume and shape)    liquid (relatively fluid, definite volume)   gas (easily compressible fluid)

plasma

4th state of matter, no definite shape, particles can conduct electric currents, found in fire or lighting

thermal enegry

 Most matter expands when it gets hot and contracts when it cools

Expansion

increase in area, length or volume

Changes of state of matter

Evaporation + condensation - Liquid-gas and Gas-Liquid Freezing + Melting - Liquid-Solid and Solid-liquid

Sublimation + Deposition - Solid-Gas and Gas-Liquid

Endothermic reaction

Absorbs energy

Exothermic energy

Release energy

Conduction

The transfer of energy by touch

Convection

Transfer of thermal energy by motion of particles 

Radiation

Transfer of heat by light or space

Scientific Method

use of controlled methods to collect observable evidence to answer questions about natural phenomena