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Quarter 1 exam
chapters 1 - 5 & 13!
71
Science
8th Grade
10/25/2007

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Cards

Term
matter that makes up an object
Definition
is mass.
Term
The production of heat when two substances are mixed might indicate that a
Definition
chemical change is occuring
Term
less helium would be needed to fill a balloon on a
Definition
hot day
Term
an example of a chemical property is
Definition
reactivity
Term
clouds are an example of a
Definition
colliod
Term
matter that consists of one type of atom or one type of molecule is a
Definition
pure substance
Term
substance composed of a single kind of an atom is an
Definition
element
Term
a physical property that is a measure of the amount of matter in an object is
Definition
volume
Term
matter that contains two or more pure substances is a
Definition
mixture
Term
substance made of atoms or two or more different elements joined by chemical bonds is called
Definition
a compound
Term
99% of matter in the universe is
Definition
plasma
Term
J.J Thompson discovered
Definition
electrons
Term
 __________ is larger than a decimeter
Definition

meter


Term
the international system of units was first called
Definition
the metric system
Term
The SI base unit for temperature is
Definition
kelvin
Term
scientists express very large or small number
Definition
mulitplied by 10 to the appropriate power
Term
another name for a change that takes place when bonds between atoms are broken or formed to make new substances in a
Definition
chemical reaction
Term
the center of an atom is a dense region consisting of protons and neutrons called th
Definition
nucleus
Term
what is the one place with temperatures high enough for nuclear fusion to happen?
Definition
the sun's core
Term
in Thompson's "plum-pudding" model of the atom, the plums represent
Definition
electrons
Term
an atom of gold with 79 protons 79 electrons and 118 neutrons would have a mass number of
Definition
197
Term
if an isotope of uranuim - 235 has 92 protons how many protons does uranium - 238 have?
Definition
92
Term

how did Democriatus describes atoms ?

Definition
small hard particles
Term
if hydrogen -1 has one proton how many protons does hydrogen-2 have?
Definition
1!
Term
have the same number of protons
Definition
isotopes
Term
a neutral calcuim (CA) atom contains 20 protons 20 neutrons and 20 electrons. this atom becomes an ion when it loses two electrons. whut is the ion charge?
Definition
postive
Term
the number of protons in the nucleus of an atom is the
Definition
atomic number
Term
the sum of protons and neutrons in an atom are the
Definition
mass number
Term
mass of an atom expressed in atomic mass units is the
Definition
atomic mass
Term
the raised surfaces on Thompson's "plum-pudding" model are describing
Definition
electrons
Term
mendeleev found that properties of known elements followed a pattern that repeated every
Definition
7 elements
Term
how would you describe most medals
Definition
they can be drawn into thin wires
Term
very reactive
Definition
alikali medals
Term
medals that have two outer-level electrons are
Definition
alikali earth medals
Term
elements with radioactive atoms are
Definition
actinides
Term
very reactive non-medals are
Definition
halogens
Term
unreactive non-medals that dont react with other elements under normal conditions are
Definition
noble gases
Term
medals in groups 3-12 that dont give away their electrons as easily as atoms of groups 1 & 2 are
Definition
transition medals
Term
the number beneath carbon indicates the
Definition
atomic number
Term

the process by which a large nucleus splits into two smaller nuclei and releases energy is called

Definition
nuclear fission
Term
how can large atoms be forced to undergo nuclear fission
Definition
by hitting the atoms with neutrons
Term
the nuclear fission of the uranium in one fuel pellet releases as much as energy as burning
Definition
1,000 kg of coal
Term
a continuous series of nuclear fission reactions is called
Definition
a nuclear chain reaction
Term
when two or more nuclei that have small masses combine, or fuse, to form a larger nucleus, it is called
Definition
nuclear fusion
Term
matter in which electrons have been removed from atoms is called
Definition
plasma
Term
instead of using kelvins, scientists often measure temperature in a unit called
Definition
celsius
Term
anything that has mass and takes up space is called
Definition
matter
Term
we know that air is matter because
Definition
it has mass
Term
the smallest unit of an element that maintains the properties of that element is
Definition
an atom
Term
a homogenous mixture that appears to be a single substance is an
Definition
solution
Term
a characteristic of matter that can be ovserved or measured without the matter going through a chemical change is called
Definition
physical property
Term
a property of matter that describes a substance's ability to participate in chemical reactions and form new substances is called
Definition

a chemical property

Term
when baking soda and vinegar react to form bubbles of cabon dioxide, it is evidence of baking soda's
Definition
reactivity
Term
the chemical property that indicates a substance can burn is
Definition
flammability
Term
the law of conservation of mass states that in ordinary chemical or physical changes
Definition
energy is not created or destroyed
Term
what change occurs in a boulder when it erodes into sand?
Definition
its form changes
Term
the chemical changes that occur when your body uses sugar
Definition
obey the law of conservation of mass
Term
a change in which one or more substances change into entirely new substances with different properties is a
Definition
chemical change
Term
another name for a change that takes place when bonds between atoms are broken or formed to make new substances is a
Definition
chemical reaction
Term
particles in matter are always moving because they have
Definition
energy
Term
whether a substance such as bromine is a solid,liquid,or gas its __________________________ are the same
Definition
chemical properties
Term
Democritus's theory about atoms is
Definition
atoms are made of single material
Term
part of atom that is dense, postivily charged
Definition
nucleus
Term
who thought " atoms of the same element are exactly alike"
Definition
Dalton
Term
a way to increase the pressure of a gas in a container that cannot expand is to
Definition
increase the temp.
Term
most chemicals are reversible. true or false
Definition
true
Term
the chemical changes that occur when your body uses sugar is
Definition
obey the law of conservation of mass
Term
extra substances produced in industry during chemical and physical changes are called
Definition
byproducts
Term
the ablity of two substances to react and form a new substance such as carbon dioxide is a
Definition
chemical property
Term
substance composed of a single kind of atom
Definition
element
Term
substance made of atoms of two or more different elements joined by chemical bonds
Definition
compound
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