chapter 2: matter

matter is anything with

matter is anything with

mass and volume

a substance

a form of matter with a uniform composition and unchanging properties that are both physical and chemical

physical properties

observed without changing a substances chemical composition: color, hardness, and density

chemical

cannot be observed without changing composition of a substance, meaning they change color, hardness and density

Important physical properties

colorless/has color

melting point

boiling point is 100 degrees Celsius

conducts electricity

density is 1g/cm

heat conductivity

brittleness

hardness

shine

important chemical properties

ability to combine with another substance

remains unchanged in the presence of nitrogen

acid resistance

combustible

odor

flammable

dissolves in water

sour taste

rusting

does a gas have both the shape and volume of its container?

true

can the words water vapor be used interchangeably?

false

Liquids contract when heated

false, they expand

chemical change

a chemical reaction that involves 1 or more substances changing into a new substance

reactants

starting substances in a chemical reaction

products

the new substances formed in a chemical reaction

chemical equation

shows the relationship between the reactants and the products in a chemical reaction

law of conservation of mass

Mass is not created nor destroyed in any chemical or physical change

a substance that cannot be separated into simpler substances by physical or chemical means is a??

an element

The chemical combination of two or more different elements produces a?

compound

What are the horizontal rows on the periodic table called?

periods

What are the vertical columns on the periodic table called?

groups or families

matter consists of 2 subcategories:

substances and mixtures

What are the 2 mixtures?

homogeneous and heterogeneous mixtures

homogenous mixture

a mixture in which the composition is uniform throughout and you cannot notice/find the products used to make it. THEY ARE SOLUTIONS

EX: coffee

heterogeneous mixture

A mixture in which different components can be distinguished easily

EX: salad, trail mix

substances

include elements and compounds, elements are made up of only 1 kind of atom, compounds are made up of 2 or more elements, and they are chemically combined.

NOTE: there are 118 atoms and 92 of them are natural, 26 of them are man made