CHEM 1010 Module 3

Elements that are in the same _________ have a tendency to have very similar chemical properties due to periodic trends.

Group

The repeating trends that take place when examining the elements are called ________.

Periodicity

What is the name of the following compound: AgBr?

Silver Bromide

Why can't the elements of a compound be separated from one another by physical means?

The atoms in a compound are too tightly bound to one another.

Which of the following statements best describes an element?

a. A material with more than one type of atom b. A material consisting of only one type of atom. c. A material that is pure. d. A material that exists only as individual atoms . e. A material that has consistent physical properties regardless of temperature or pressure. Correct answer is B.

Which of these properties describes a metal?

a. Doesn't conduct electricity very well. b. Transparent c. Conducts heats very well d. Fragile e. Brittle Correct answer is C.

Which statement best describes a compound?

a. None of the answers are correct b. A mixture of more than one element. c. A mixture of atoms d. A material that is made up of a single type of atom. e. A material that is made up of a combination of atoms bonded together Correct answer is E.

Which of the following is an example of a chemical change?

a. breaking a glass window b. aftershave or perfume on your skin generating a smell. c. None of the changes are chemical changes. d. a piece of metal expanding when heated, but returning to original size when cooled. e. Gasoline being used in the engine of a car producing exhaust f. Water freezing into ice crystals. Correct answer is E

What is the name of the following compound: CaCl2?

calcium chloride

What is the name of the following compound CO2?

carbon dioxide

What is the name of the following compound: SF3?

sulfur trifluoride

What is the atomic symbol for potassium?

K

How many atoms of Oxygen (O) are in HCIO4?

4

A sample of water that is 99.9999 percent pure contains 0.0001 percent impurities. Consider from Chapter 1 that a glass of water contains on the order of a trillion trillion (1 × 1024) molecules. If 0.0001 percent of these molecules were the molecules of some impurity, about how many impurity molecules would this be?

1,000,000,000,000,000,000 (one million trillion: 1 x 10^18)

Compared to microtechnology, nanotechnology focuses on a scale that is about

1000 times smaller.

The prefix "nano-" means _________.

10^-9

Allowed levels of lead in drinking water are 15 ppb. How many grams of lead would you consume if you drank 2.0 L of this water?

3.0 x 10^-5 g

Fish require a dissolved oxygen concentration of about 7 ppm. What is the concentration in ppb (parts per billion)?

7,000 ppb

Mixtures can be separated into their components by taking advantage of differences int he chemical properties of the components. Why might this separation method be less convenient than taking advantage of differences in the physical properties of the components?

A chemical property involves a chemical change so that you no longer have what you had.

What is the difference between a compound and a mixture?

A mixture can be physically separated into its components; a compound cannot be physically separated into its components.

Water and ethanol can be separated by heating the ethanol until it boils away from the water. What type of change is this?

A physical change.

How would you classify the following material? Milk

A suspension

Which of the following is a metalloid?

Antimony (atomic no. =51)

A chemical reaction is synonymous to a _____________.

Chemical change.

The atomic symbol for cobalt is

Co

What is the name of the following compound: N2O4?

Dinitrogen tetroxide

When blue food coloring is dissolved in water, the result is a ________.

Homogeneous mixture called a solution.

A chemical change involves a change in _____________.

How atoms are bonded.

Oxygen atoms are used to make water molecules. Does this mean that oxygen, O2, and water, H2O, have similar properties?

No, compounds are uniquely different from the elements in which they're made.

How soon will nanotechnology give rise to commercial products?

There are already commercial products on the market that have been developed using nanotechnology.