Chem Ch. 2 Notes

Energy and Matter

Work -

the capacity to move an object to move an object over a distance against a resisting force

Radiant energy

sunlight

Kinetic Energy

energy of motion

Types of Kinetic energy:

Mechanical energy

Thermal energy

Mechanical Energy

moving parts of a machine

Thermal energy-

energy is due to random internal motion of particles in matter.

Potential Energy-

energy stored in an object due to its position

Types of potential energy:

Gravitational energy

Electrical 

Chemical

Chemical energy

exists because of the arrangement of the particles that make up a substance

Jewels and Calories

units to measure energy

Law of Conservation energy

matter is neither created nor destroyed

Fahrenheit, Celsius, and Kelvin

Ways to measure temperature

Kelvin

is used for calculations in science.

Celsius

is used for recording science measurements.

Matter

Defined as anything that has mass and volume.

Plasma

is found in stars and that’s all we will say about this state of matter.

What is not a Solid Property

Molecules have freedom of movement

What is not a Property of Liquids

Does hold shape (does not take shape of it’s container)

What is not a Property of Gases

Does have definite shape

How do we change from each state of matter?

Either adding or losing heat/energy

Chemical properties ~

properties that can not be observed without altering the substance

Chemical Change/reaction-

the identity of the substance is altered.

Physical Change-

do not alter the identity of the substance.

Elements ~

defined as a substance that cannot be separated into similar substances by a chemical change.

Compounds

Defined as two or more elements in a fixed proportion

Pure substances

Defined as a substance made of one kind of material with a unique set of chemical and physical properties.

What are the types of mixtures:

Homogeneous and Heterogeneous

Homogeneous

Two or more substances in a mixture that are evenly mixed.

Heterogeneous

Two or more substances in a mixture that visibly have distinguishable parts

Ways to separate Mixtures:

Distillation, Filtration, Chromatography

Distillation

uses boiling points of two different substances to separate.

Filtration

separates between a solid and a liquid.

Chromatography-

a solution is separated by allowing it to flow along a stationary substance.