Chemistry Flashcards
(35 cards)
Melting
When something in a solid form changes into a liquid.
melting Ice or metals
Freezing
The reverse process of melting.
Heat is removed from a material atoms slow down until they are “locked In” (solid state)
freezing point of water is 0C or 32F
Boiling
When heat is added to a liquid, small bubbles of vapor form at the bottom.
when they escape the liquid enter the gas phase into the air.
Evaporazition
The change from liquid to a gas (vapor) that is below the boiling point.
puddles on a sidewalk that disappear into the air.
Condensation
The change from gas to liquid.
when a vapor is cooled the molecules loose kinetic energy (slow down)
Reverse of evaporation.
Sublimation
The change from Solid directly into gas.
Dry ice is a good example. It doesn’t melt just starts to smoke.
What are the 3 common phases of matter?
Solid, Liquid, Gas
Define Chemistry term “matter”
Anything that has mass and occupies space.
The amount of material in a substance.
Difference between Chemical and Physical change.
Chemical change is when a reaction happens and a new form is made, and physical change is when something changes shape. (melting, freezing, boiling, evaporation, condensation, sublimation.
Mixture
Two or more pure substances that physically combine.
Items can be put together in any ratio.
Solution
A homogeneous mixture.
molecules of two substances intermix evenly but are not bond together.
Example: sugar or salt in water, no longer visible to the eye. (can’t identify the parts)
Pure Substance
Homogeneous
matter that has the same composition and properties. have the same composition throughout.
examples: water, sugar, silver, mercury.
Solute
A substance in a solution that dissolved into another substance.
Sugar in water, sugar is the solute (minor component of the mixture).
Solvent
substance that dissolves the other substances.
sugar in water, water is the solvent.
Solubility
How easy something will or will not dissolve in something else.
Sugar in water is very soluble.
Atom
Smallest particle of an element that can exists either alone or in combination with other Atoms.
Element
Most basic building block of nature which all things are made of.
Carbon, oxygen, hydrogen, zinc, copper.
Compounds
Pure substances made from two or more different elements “chemically” combined in fixed proportions.
H2O (2 hydrogens, 1 oxygen)
CO2 ( 1 carbon 2 oxygen “dioxide”)
Molecule
Two or more Atoms chemically bonded together.
Smallest unit of bonds that can exists.
Examples: H2, O2, CL2
Solid
Matter that has definite shape and volume.
Liquid
Matter that has no definite shape, but definite volume.
Gas
Matter has no definite shape or form.
Mass is measured in?
Kilograms.
Atom
Smallest particle of an element.
Can exist alone, or in combination with others of that element.
