7th Grade Science Final Exam

ductile

capable of being shaped or bent or drawn out

colloid

a mixture with properties between those of a solution and fine suspension

atoms

the smallest unit of matter that has the characteristics of an element; consists of three main types of subatomic particles: protons neutrons and electrons.

atmosphere

the mass of air surrounding the Earth

Mendeleev

Russian chemist who developed a periodic table of the chemical elements and predicted the discovery of several new elements (1834-1907)

heterogeneous mixture

a mixture in which different materials can be distinguished easily

atomic number

the order of an element in Mendeleyev's table of the elements

water cycle

The continuous process by which water moves from Earth's surface to the atmosphere and back

condensation

the process of changing from a gaseous to a liquid or solid state

matter

that which has mass and occupies space

electrons

negatively charged particles

protons

Positively charged particles

neutrons

the particles of the nucleus that have no charge

ground water

underground water that is held in the soil and in pervious rocks

atom

(physics and chemistry) the smallest component of an element having the chemical properties of the element

troposphere

the lowest atmospheric layer

stratosphere

the atmospheric layer between the troposphere and the mesosphere

exosphere

the outermost atmospheric layer

mesosphere

the atmospheric layer between the stratosphere and the thermosphere

humidity

the amount of water vapor in the air

malleable

capable of being shaped or bent or drawn out

conduction

the transmission of heat or electricity or sound

climate

the weather in some location averaged over some long period of time

How did chemists change Mendeleev's periodic table in the early 1900s?

They used atomic number instead of atomic mass to organize the periodic table

This is an example of a heterogeneous mixture?

soil

From Earth to space, the main layers in our atmosphere are _________________

troposphere, stratosphere, mesosphere, thermosphere.

The atomic number of an element is based on the ______________________

number of protons

mixture containing particles that are too small to be seen easily but are large enough to scatter a light beam is called a ______________

colloid

As you rise upwards in the atmosphere, air pressure ___________________

decreases

Water moves continually between the atmosphere and Earth's surface in the process called _______________

water cycle

In an atom, the number of protons equals the number of ________________

electrons

this is the primary source of ground water

precipitation (rain, dew, etc.)

The change from liquid to solid, or the reverse of melting, is called

freezing

The layer of our atmosphere in which weather occurs is the

troposphere

solid

definite shape and definite volume

liquid

definite volume but indefinite shape

gas

indefinite volume and shape

water vapor is the form of a ________

gas

Climates are classified by two things: ___________ and _____________

precipitation and temperature

the average, year-after-year conditions of temperature, precipitation, winds, and cloud in an area are known as its _____________

climate