First Quarter Review Flashcards
dependent variable
output of the independent variable
plotted on the y-axis
hypothesis
an educated guess about how things work
form: if__ then__
independent variable
a variable that is controlled by scientist
plotted on x-axis
qualitative data
data that describes how? and what?
quantitative data
data that describes how many? or how much?
has numbers
matter
anything that has mass and takes up space
mass
the amount of matter in an object
measure of inertia
chemical property
a property of matter that describes a substance’s ability to participate in chemical reactions
ex. inflammability
chemical change/reaction
a change that occurs when one or more substances change into entirely new substances with different properties
ex. wood burning, carbon and oxygen(2) form carbon dioxide, sour milk
physical property
a characteristic of a substance that does not involve a chemical change
ex. density, color, hardness
physical change
a change of matter from one form to the other without a change in chemical properties
ex. salt dissolving in water
all changes in state are physical changes
atom
the smallest particle in which an element can be divided and still be the same substance
atomic number
the number of protons
identifies the element
determines chemical properties
isotopes
atoms that have the same number of protons but have different number of neutrons
same atomic number different mass number
atoms of the same element with different masses
mass number
number of protons + number of neutrons
electron
the negatively charged particles in an atom
likely found in the electron cloud
mass: tiny
energy levels
max. # of electrons of each level
a layer of electrons formula for finding max # of electrons of each level: 2n^2 1st- 2 2nd- 8 3rd- 18 4th- 32
valance electrons
electrons on the outermost shell of electron cloud
determines the atom’s chemical properties
proton
positively charged particle
found in the nucleus
mass: 1+
neutron
no charge particle
found in nucleus
mass: 1amu
slightly bigger mass than proton
gas
the state of matter does not have a definite volume or shape
disorganized
far apart
move in straight line until they bounce off something else
lot of energy
liquid
the state of matter that has a definite volume but not a definite shape
particles slide past each other
disorganized
solid
the state of matter in which the volume and shape of a substance are fixed
particles are close together
organized
move by vibrating
fluids
liquid
gas
plasma
boiling
when a liquid turns into a gas
freezing
when a liquid turns into a solid
melting
when a solid turns into liquid
condensation
when a gas turns into a liquid
sublimation
when a solid turns into a gas
deposition
when a gas turns into a solid directly
substance
matter that has uniform and unchanging properties
cannot be separated by physical changes
compound
a pure substance composed of two or more elements chemically combined
can be broken down by chemical reactions(means)
definite ratio of components
element
a pure substance that cannot be broken down by physical or chemical means
mixture
a combination of two or more substances that are not chemically combined
2 or more components that keep their physical characteristics
can be separated by physical means(changes)
2 types: heterogeneous and homogeneous
solution
homogeneous mixture smaller part: solute largest part: solvent can't be filtered or settled out on standing can't scatter light
solute
smaller part of solution
dissolved into solvent