chemistry unit 1: matter

Matter

Matter

anything that has mass and takes up space/has volume

Mass

the amount of matter in a substance

Volume

the measure of how much space something takes up

Weight

the force of gravity on an object or substance

Phases

-the state of matter a substance is in

-can also describe the different parts of regions in a sample

Physical Change

qualities of a substance that are demonstrated without changing the chemical composition of the substance

Chemical Properties

how matter behaves when it changes into another kind of matter

Chemical Change

when one or more substances are changed into more new substances

Homogeneous

-a sample of matter that has the same properties

-uniform in composition

-equal volumes of mixtures have the same composition (same # and kind of atoms)

Heterogenous

-a sample of matter that consists of two or more phases

-Not uniform in composition

-Equal volumes of mixtures have different compositions

Compounds

two or more elements combine in fixed proportions

Substance

-matter that has a definite and unchanging set of properties

-all samples have identical composition

Mixtures

-generally contains two or more kinds of matter in varying proportions

-Not true substances

-Can be heterogeneous or homogeneous

Energy

the ability, or capacity, to do work

Physical Energy

energy a body possesses because of its position with respect to another body

Chemical Energy

stored in the bonds of chemical compounds

Kinetic Energy

energy of motion

Temperature

measure of thermal energy (how hot or cold something is), average kinetic energy of a substance

System

a group of interacting or related elements that folow a set of rules to form a united whole

Law of Conservation

states that energy can not be created or destroyed

Density

measurement on how tightly packed a substance is

Structure of Matter

-atoms that join together to form molecules

-type and arrangement of atoms determine the type of matter

"Phases"

different phases

solid, liquid, gas

solid

Definite shape and volume

liquid

definite volume but no definite shape.

gas

no definite shape or volume

Composition of Matter

-made up of different elements as stand alones or in different combinations

atoms

-Smallest part of an element and building blocks of matter

-Retains the properties of elements

-Made of protons, neutrons, & elections

-determines element identity

elements

made of one atom and cannot be broken down into simpler substances

bonds

-attractive forces in matter

-are related to the strength of attractive forces between smaller particles

-the angle between the bonds (way they are arranged) determine the shape of the molecule

compounds

-occurs when 2 or more elements combine in fixed proportions by mass

-chemically combined compounds can only be separated by chemical means

Substances

-any variety of matter that is definite and unvarying set of properties

-all samples have identical composition

Compounds vs. Mixtures

-Compounds have single sets of properties

-Mixtures have properties of each of its components

-Compounds always have a fixed composition

-Mixtures do not have a fixed composition

potential energy

-as potential energy decreases, it becomes more stable

- As increases, it becomes less stable

-particles that attract each other have high potential energy and low stability when they are far apart

-they have low potential energy and high stability when they are close together

Chemical energy

-type of potential energy

-stored in the bonds that result from the attractive forces between particles

-stronger bonds mean greater stability

Kinetic

-closely related to temperature

-can be changed into potential energy without losing any (Law of Conservation)

Physical Changes

change in properties such as texture, shape, or state

Chemical Changes

represents the formation of a new substance after atoms are rearranged in a chemical reaction

heat

measure of the total energy in a system

calories

-Units of heat that measure the energy used by the body

-i.e. kilo calories

temperature

A measure of the average kinetic energy of the particles of a substance.

Farenheit vs Celsius vs Kelvins

different temperature scales

Farenheit boiling and freezing point

212, 32

Celcius boiling and freezing point

100, 0

kelvins boiling and freezing point

373, 273