Chapter 3 : Matter and Energy

Question 1

What did Robert Boyle do?

Answer 1

He established the importance of science experiments . He made sure to describe his work in detail so someone else could repeat the experiment.

Published a book and marked a turning point in science by suggesting theories were no better than the experimental methods that supported them

rejected the Greek notion of earth, air, fire, and water as the basic elements

proposed an element was a substance that could not be broken down any smaller

Question 2

Define: Physical state

Answer 2

the condition of matter existing as a solid liquid or gas

Question 3

describe the solid state

Answer 3

matter has a fixed shape and fixed volume. the particles are tightly packed, in a rigid position and cannot be compressed

Question 4

describe the liquid state

Answer 4

matter has a variable shape but a fixed volume. the particles are loosely packed, free to move around and compress only slightly

Question 5

describe the gas state

Answer 5

tiny particles of matter are widely spaced apart and uniformly distributed in its container. if volume increases, the gas expands and the particles move farther away from each other. if the volume decreases, the gas compresses and the particles move closer to each other.

Question 6

give an example of a solid, liquid, and gas

Answer 6

ice, water, steam

Question 7

Define: sublimation

Answer 7

a direct change of state from a solid to a gas without becoming a liquid

Question 8

Define: deposition

Answer 8

a direct change of state from a gas to a solid without becoming a liquid

Question 9

A sample of matter is _____ if its properties are indefinite and vary

Answer 9

Heterogeneous

Question 10

A sample of matter is _____ of it its properties are definite and constant

Answer 10

Homogeneous

Question 11

Define: heterogeneous mixture

Answer 11

matter having an indefinite composition and variable properties

can be separated onto pure substances with physical methods

Question 12

Define: homogeneous mixture

Answer 12

matter having a definite composition but variable properties from sample to sample such as alloys and solutions

Question 13

Define: alloy

Answer 13

a homogeneous mixture of two or more metals

Question 14

Define: substance

Answer 14

matter with a definite composition and constant properties. also called a pure substance. such as elements and compounds

Question 15

Define: compound

Answer 15

a pure substance that can be broken down into two or more simpler substances by a chemical reaction

Question 16

Define: element

Answer 16

a pure substance that cannot be broken down by an ordinary chemical reaction

Question 17

what is the most abundant element on earth

Answer 17

oxygen

Question 18

what are the three most abundant elements on earth

Answer 18

oxygen, silicon, and aluminum

Question 19

what six elements make up over 99% of the human body

Answer 19

oxygen, carbon, hydrogen, nitrogen, calcium, and phosphorus

Question 20

Define: chemical symbol

Answer 20

an abbreviation for the name of a chemical element

Question 21

Define: atom

Answer 21

the smallest particle that represents an element

proposed by English chemist John Dalton in 1803

indivisible spherical particles

Question 22

who proposed the current symbol system?

Answer 22

Swedish chemist JJ Berzelius

Question 23

Define: metal

Answer 23

an element that is generally shiny in appearance, has a high density, high melting point, and is a good conductor of heat and electricity. it is said to be malleable and ductile

Question 24

Define: malleable

Answer 24

the property of a metal that allows it to be hammered or machined into a foil

Question 25

Define: ductile

Answer 25

the property of a metal that allows it to be drawn into a wire

Question 26

Define: non-metal

Answer 26

an element that is generally dull in appearance, has a low density, low melting point, and is not a good conductor of heat and electricity, many occur in a dull solid state. not malleable or ductile but crush into a powder

Question 27

Define: semi-metal

Answer 27

also known as metalloid. an element that is generally metallic in appearance and haas properties midway between those of a metal and nonmetal