Chemistry Midterm

Based on your senses and observations

Involves numbers and measurements

Title, purpose, procedure, data and observations, calculations, conclusion and questions

do not depend on the amount of matter present

depend on the amount of matter that is present

Physical - does not create a new substance, atoms are not rearranged into different compounds; Chemical - converts one substance into another; atoms are rearranged

2 or more different elements chemically combined; composition always remains the same

A molecule composed of one kind of atom; cannot be broken into simpler units by chemical reactions.

an item that consists of only one material throughout or a combination of multiple materials that cannot be mechanically disjointed, excluding surface coatings

a material with a composition that varies from one point to the next within its structure

A combination of two or more substances that are not chemically combined and have varying composition (wood, soda, coffee, air)

Groups of two or more atoms held together by chemical bonds

Pure substances have definite melting points; mixtures do not

filtration, distillation, crystallization, chromatography, magnet, sorting by color, centrifuging

Have definite shape and volume, atoms are tightly packed and vibrate in place, strong force of attraction between particles

definite volume but no definite shape, flow, looser attractive forces

no definite volume or shape, weak attractive forces, flow

Characteristic that can change without turning it into a different substance (odor, volume, state, density, melting point, boiling point)

Characteristic that describes the ability of a substance to change to a different substance

change that does not affect a substance's composition

substance becomes another substance (wood burning, rusting of steel, digestion of food, growth of plants)

mixture of a metal

always have the same composition (elements or compounds)

Must have mass and volume

Mass is a measurement of the amount of matter something contains (makeup stays the same everywhere), while weight is the measurement of the pull of gravity on an object (changes on different planets).

heterogeneous, shows Tyndall effect, will not settle out over time, think snickers bar or tapioca pudding

heterogeneous, shows Tyndall effect, settles out over time

Homogeneous, no definite formula, type of mixture

1. Observations 2. Formulate hypothesis 3. Experiment -- Theory, prediction, experiment repeat enough and could end up with a law

As temperature increases, so does pressure, and as it decreases, so does pressure (because temperature increases particle movement, they move more often and therefore hit the sides of things more, increasing pressure)

part/whole x 100

Expressing the smallest whole number ratio of atoms in a compound

The actual formula of a compound

This is a test tube, and its purpose is to hold, mix, or heat small quantities of substances

This is an iron ring, and its purpose is to hold up whatever is placed on the Bunsen burner

This is a ring stand and it holds an iron ring. Commonly, a Bunsen burner is placed beneath it to heat whatever rests on it

This is a test tube rack and its purpose is to hold test tubes

This is a Bunsen burner and its purpose is to heat things

These are crucible tongs and they hold the crucible

These are beaker tongs and they hold the beaker

This is a dropper pipette and its purpose is to transfer small amounts of liquid

This is a watch glass and is typically used for evaporation and weighing solids

This is a glass stirring rod and it is for stirring solutions/mixtures

This is a thermometer and it is for checking the temperature of something

This is a scoopula and it is for scooping small amounts of things and removing/scraping substances

This is a test tube holder and its purpose is to carry/hold test tubes

This is a pipestem triangle and its purpose is to hold up the crucible while it is being heated above the Bunsen burner

This is a crucible and cover, and its purpose is to hold, typically solids, to give them somewhere to be while they are being burned/heated over a Bunsen burner

These are forceps and they help hold/carry small things

This is a mortar and pestle and they are for grinding/crushing solids

This is a graduated cylinder and its purpose is to measure amounts of liquid in milliliters

This is an evaporating dish and it is used to allow things to heat/evaporate over time

This is a wire gauze and it is for protecting glassware on a Bunsen burner by diffusing the heat

This is a beaker and it is for measuring liquids, containing liquids/solids, and for holding things that may be used in a reaction