Praxis Middle School Science-Matter and Energy

Question 1

matter

Answer 1

makes up everything in the world

takes up space and has mass

Question 2

mass

Answer 2

the measure of the amount of matter in an object

Question 3

weight

Answer 3

the measure of earth’s pull of gravity on an object

also the pull of gravity between other bodies-the mass of an object remains the same but the weight changes depending on gravity.

Question 4

volume

Answer 4

the amount of cubic space that an object occupies

Question 5

density

Answer 5

the mass of a substance contained per unit volume

Question 6

physical property

Answer 6

a characteristic that can be observed without changing the identity of a substance

Question 7

chemical properties

Answer 7

describes the capacity of a substance to be changed into new substances

Question 8

the stars manufactured

Answer 8

every chemical element heavier than hydrogen

the thing cloud (planetary nebula) of gas and dust, from which the sun and its planet formed, was struck by the shock waves and remnant matter from exploded stars outside of our galaxy

Question 9

solar system

Answer 9

inner planets’ composition: reflects the sun’s attraction of the heavier elements

outer planets’ composition: reflects the lighter, less dense elements attracted less by the sun’s gravitational mass.

Question 10

on each planet, heavier elements…

Answer 10

sink inward to form the core

lighter elements form the atmosphere

Question 11

our planet’s earliest history…

Answer 11

violent.

struck by meteorites

Question 12

the earth’s birthing process produced…

Answer 12

frequent eruptions that caused water to rise to the surface, and the solar system contributed to additional water to the primordial seas.

Question 13

the percentage of sodium in the earth’s oceans has

Answer 13

not varied appreciably for at least 600 million years

Question 14

earth’s core composed of

Answer 14

iron and nickel

Question 15

earth’s crust is rich in

Answer 15

silica

Question 16

atmosphere consists of

Answer 16

78% nitrogen and 21% oxygen

Question 17

how many naturally occurring elements are their in the universe?

Answer 17

92

Question 18

of the 92 naturally occurring elements…

Answer 18

only 8 make up 99% of earth’s mass.

Question 19

physical change

Answer 19

does not create a new substance

does not rearrange atoms into different compounds

ex: bending a nail

Question 20

chemical change

Answer 20

converts one substance into another by rearranging atoms to form a different compound

ex: iron oxide (rust) is present in a rusty nail

Question 21

solid

Answer 21

matter that has definite shape and volume

Question 22

liquid

Answer 22

matter that has definite volume, but no shape

Question 23

gas

Answer 23

no shape or volume

spreads out to occupy entire space of whatever container it is in

Question 24

energy

Answer 24

the ability to cause change in matter

Question 25

evaporation

Answer 25

the process of changing a liquid to a gas

Question 26

condensation

Answer 26

the process of changing a gas to a liquid

Question 27

composition reaction

Answer 27

two or more substances combine to form a compound

Question 28

decomposition reaction

Answer 28

a compound breaks down into two or more simpler substances

Question 29

single replacement reaction

Answer 29

decomposition reaction; a compound breaks down into two or more simpler substances

Question 30

double replacement reaction

Answer 30

parts of two compounds replace each other, seeming to switch partners

Question 31

principle of conservation of mass

Answer 31

the total mass of system is constant

Question 32

when matter changes phase

Answer 32

mass remains constant

Question 33

law of conservation of energy

Answer 33

matter is neither created or destroyed, but merely changes state either giving off or absorbing energy in the process

Question 34

joules

Answer 34

measurement of work as the product of force on an object and the distance through which the object is moved

Question 35

thermal energy

Answer 35

the energy moving atoms and molecules

Question 36

chemical energy

Answer 36

the energy that bonds atoms and molecules together

Question 37

nuclear energy

Answer 37

energy of moving the nucleus of an atom

Question 38

mechanical energy

Answer 38

energy of moving objects

Question 39

potential energy

Answer 39

energy stored in an object due to its position

Question 40

elastic potential energy

Answer 40

energy stored in elastic (stretchable) objects such as rubber bands or springs

Question 41

gravitational potential energy

Answer 41

energy of an object has when it is in an elevated position

Question 42

kinetic energy

Answer 42

energy of an object has due to its mass and motion

Question 43

four states of matter

Answer 43

liquid solid gas plasma

Question 44

plasma

Answer 44

a superheated, molten gas, and not all physicists or textbooks agree that it is a separate state of matter