Chemistry Chapter 7 (copy)

chemistry

The study of the properties of matter and how matter changes

matter

anything that takes up space and has mass

atoms

small particles that is the building block of matter

nucleus

Control center of the atom

protons

Positively charged particles

electrons

Negatively charged particles

electron cloud

a region around the nucleus of an atom where electrons are likely to be found

substances

matter with a composition that is always the same

elements

a substance that consists of atoms of only one kind

compounds

molecules that contain more than one element

chemical formula

A combination of chemical symbols and numbers to represent the compound

mixtures

A combination of two or more substances that are not chemically combined

heterogenous mixture

A mixture in which substances are not evenly mixed

homogenous mixture (solution)

A mixture in which substances are evenly distributed throughout the mixture

solutions

a mixture where substances are distributed evenly. has a solvent & solute.

dissolve

to form a solution by mixing evenly

physical properties

a characteristic of matter that you can measure or observe without changing the identity of matter.

solids

have a definite shape and volume

liquid

the state of matter that has a definite volume but not a definite shape

gas

a form of matter that does not have a definite volume or shape

mass

the amount of matter in an object. (grams, g)

weight

the force of gravity on an object

volume

the amount of space an object takes up

melting point

the temperature at which matter changes from a solid to a liquid

boiling point

the temperature at which a liquid changes from a liquid to a gas

density

the mass per unit of volume of matter (mass\volume)

conductivity

the ability of matter that conducts heat.

solubility

the ability for one substance to dissolve in another substance.filtration

filtration

separating by particle size

distillation

separation by melting or boiling points

density

separating by lowest to highest density

magnetism

attractive force for some metals.

physical changes

a change in size, shape, form, or state of matter in which the matter's identity stays the same.

melting

change from a solid to a liquid

boiling

The change of state from a liquid to a gas

evaporation

takes place at the surface of a liquid; below the boiling point.

sublimation

A change directly from the solid to the gaseous state without becoming liquid

frezzing

change of matter from a liquid state to a solid state

condensation

The change of state from a gas to a liquid

deposition

gas to solid

dissolving

one substance breaks into smaller particles that mix evenly throughout another substance.

conservation of mass

particles in matter present before a physical change are the same as those present after a physical change.

chemical properties

a characteristic of matter that can be observed as it changes to a different TYPE of matter ; can be observed only when the substances in a sample of matter are changing into different substances.

chemical changes

a change in matter in which the substances that make up matter are changed into other substances with NEW physical and chemical properties.

signs of chemical changes

change in color, production of gas (bubbles and odor), change in energy, formation of a percipiate

chemical reactions

when atoms bond together, new substances form