Chapter 1

Question 1

Why is chemistry, the study of matter, important?

Answer 1

If we want to understand the substances around us, we must understand the atoms and molecules that compose them—this is the central goal of chemistry.

Question 2

What does the relationship between lead and diamond show?

Answer 2

That even the same atoms can compose vastly different substances when they are bound together in different patterns.

Question 3

What is a hypothesis?

Answer 3

A tentative interpretation or explanation of the observations.

Question 4

What makes a hypothesis good?

Answer 4

A good hypothesis is falsifiable, which means that it makes predictions that can be confirmed or refuted by further observations.

Question 5

What is a scientific law?

Answer 5

A brief statement that summarizes past observations and predicts future ones.

Question 6

What is a scientific theory?

Answer 6

A scientific theory is a model for the way nature is and tries to explain not merely what nature does but why. Theories are validated by experiments, but can never be conclusively proven because some new observation or experiment always has the potential to reveal a flaw.

Question 7

Why are theories considered the closest thing to truth?

Answer 7

Established theories with strong experimental support are the most powerful pieces of scientific knowledge. Theories substantiated by a large body of evidence and make correct predictions.

Question 8

Who were the first philosophers to suggest that matter was composed of small individual, indestructible, particles?

Answer 8

Leucippus and his student Democritus

Question 9

What are the 4 claims of John Dalton’s atomic theory?

Answer 9

1.
2.
3.
4.

Question 10

How the electron discovered?

Answer 10

J.J Thomson and his cathode ray tube experiment.

Question 11

How was the electron discovered?

Answer 11

J.J Thomson and his cathode ray tube experiment.

Question 12

Properties of metals:

Answer 12

• good conductor of heat and electricity
• can be pounded into flat sheets
• often shiny
• drawn into wires
• tend to lose electrons

Question 13

Properties of nonmetals:

Answer 13

• poor conductors of heat and electricity
• not ductile and not malleable
• gain electrons

Question 14

What are metalloids?

Answer 14

Sometime called semimetals, they are elements that exhibit mixed properties and are classified as semiconductors.

Question 15

Different groups of elements:

Answer 15

Alkali metals, alkaline earth metals, oxygen family nonmetals, halogens, noble gases

Question 16

Alkali metals:

Answer 16

Group 1A. All reactive metals.

Question 17

Alkaline earth metals:

Answer 17

Group 2A. Fairly reactive, but not as much as alkali metals.

Question 18

Halogens:

Answer 18

Group 7A. Very reactive nonmetals. Always found in nature as a salt.

Question 19

Noble gases:

Answer 19

Group 8A. Mostly unreactive and have full valence shells. Follow the octet (or duet) rule.