Science 101

Question 1

What are pure substances?

Answer 1

Pure substances are either the 118 currently listed elements or molecular compounds that are atomically bonded.

Question 2

What is an example of a pure substance?

Answer 2

Water (H2O), which is a combination of two hydrogen atoms and one oxygen atom.

Question 3

Is tap water considered pure?

Answer 3

No, tap water is not considered pure due to the presence of chemicals and impurities.

Question 4

What types of organisms are commonly found in lakes?

Answer 4

Living organisms such as fish, plants, and diatoms.

Question 5

How do lakes contribute to the ecosystem?

Answer 5

Lakes contain organisms that produce waste, which feeds plants, generating oxygen for fish and continuing the food cycle.

Question 6

What chemicals are often found in tap water?

Answer 6

Chlorine, chloramine, and fluoride.

Question 7

What is the purpose of aerators in taps?

Answer 7

Aerators introduce air bubbles to help reduce water usage.

Question 8

What is distilled water?

Answer 8

Water that has been heated to boiling, turned into steam, and then condensed back into water.

Question 9

Fill in the blank: The only way to get water you could call pure is to obtain _______.

Answer 9

distilled water

Question 10

True or False: Distilled water contains dissolved minerals.

Answer 10

False

Question 11

What percentage of the oxygen in our atmosphere is produced by diatoms?

Answer 11

Between 20 and 50%

Question 12

What is another name for water?

Answer 12

Dihydrogen monoxide (DAMO)

Question 13

What happens to the waste produced by organisms in lakes?

Answer 13

It sinks to the bottom to feed plants.

Question 14

What role do plants play in lakes?

Answer 14

Plants use waste to grow and generate oxygen for fish.

Question 15

Fill in the blank: Water from the cleanest lake in the world is also not considered _______.

Answer 15

pure

Question 16

Why is household water considered safe but not pure?

Answer 16

It contains chemicals and impurities.

Question 19

What is another name for water?

Answer 19

Dihydrogen monoxide (DHMO)

Water is also referred to as H2O, oxygen hydride, hydric acid, hydrohydroxic acid, hydrogen hydroxide, and oxidane.

Question 20

What does distilled water taste like?

Answer 20

Nothing

Humans generally do not enjoy flavorless water.

Question 21

Why do we need dissolved minerals in water?

Answer 21

For health

Ordinary water contains minerals that contribute to its flavor and health benefits.

Question 22

What is a pure substance example mentioned in the text?

Answer 22

Gold

24-karat pure gold consists of identical atoms and is resistant to bonding with other substances.

Question 23

True or False: The term dihydrogen monoxide is used to confuse non-chemists.

Answer 23

True

This term is sometimes used to teach lessons about believing information without fact-checking.

Question 24

Fill in the blank: Death is certain if you don’t get _______ at least every three days.

Answer 24

water

This highlights the importance of water intake, particularly during exercise.

Question 25

What is a misconception about organic farmers mentioned in the text?

Answer 25

They are cheating by using a chemical with an unfamiliar name ## Footnote This refers to the confusion surrounding the term dihydrogen monoxide as a chemical used on crops.

Question 26

What is the size of one gram of 24-karat pure gold compared to?

Answer 26

An uncooked grain of rice ## Footnote This illustrates the small size of pure gold in a gram.

Question 27

Why is it important to be critical about information encountered online?

Answer 27

To avoid believing false claims ## Footnote The text emphasizes the need for critical thinking when assessing online information.

Question 28

What happens to solids and impurities during the distillation of water?

Answer 28

They are left behind ## Footnote This process renders pure dihydrogen oxide.