Quizzes

Question 1

How many electrons in a Hydrogen (H) atom?

Answer 1

1

Question 2

How many neutrons in a Hydrogen (H) atom?

Answer 2

0

Question 3

What do the letters “amu” stand for?

Answer 3

atomic mass unit

Question 4

If an atom has 13 electrons, how many shells/orbitals will it have?

Answer 4

3

Question 5

An atom with thirteen electrons has three electrons shells/orbitals. The rules for the first 18 elements are

Answer 5

2
8
8

Question 6

What will happen to the pressure inside of a sealed tube if you raise the temperature?

Answer 6

When you raise the temperature of any system, you are adding energy. That extra energy makes the molecules more active

Question 7

What is the name of the compound NaCl?

Answer 7

The correct answer was sodium chloride. “Na” is the symbol for sodium and “Cl” is the symbol for chlorine.

Question 8

When you pour liquid nitrogen out of a beaker at room temperature it becomes a solid. T/F

Answer 8

When liquid nitrogen (N2) enters a warmer environment, it heats up. As the temperature rises quickly, the liquid becomes a gas. The whole process happens almost instantly. It happens quickly because nitrogen’s boiling point is a very low temperature (-196 degrees Celsius).

Question 9

Plasmas are all made of the same ions. They have different colors due to different amounts of electricity.

Answer 9

Plasmas can be made of many types of atoms and molecules. The color of plasma depends on what elements are being charged and ionized. The intensity may get brighter, but the basic color will not change. For example, neon (Ne) plasma emits red light while CF4 glows a blue color.

Question 10

Name a force that keeps molecules together.
Friendship
Detraction
Attraction
Phlegmatic

Answer 10

Attraction forces can keep molecules together. Actually, there are many forces involved in keeping molecules together. Attraction forces are only one type. You may hear of cohesive and adhesive properties when you study water.

Question 11

Name five states of matter

Answer 11

Solids
Liquids
Gases
Plasmas
Bose-Einstein Condensate

Question 12

Which choice is the densest state of matter?

Answer 12

The molecules in solids are more tightly packed than either liquids or gases. Density is a measure of mass over volume.

Question 13

Because electrons have been stripped away from nuclei in plasma, plasmas have a negative charge.

Answer 13

Plasmas have a neutral charge. Even though the electrons have been stripped from the atomic orbitals, the positively charged nuclei remain. The positive charges cancel out the negative charges, creating an ionized gas with equal numbers of positive and negative charges.

Question 14

Will the freezing point of a substance always be less than the boiling point? Can you explain why?

Answer 14

Yes, because boiling points always have more energy than freezing

Question 15

A system requires energy to change from a solid state to a liquid state True or false

Answer 15

True

Question 16

As the pressure on a substance changes the boiling point of the substance can go up or down?

Answer 16

True

Question 17

If the pressure of a system decreases, the rate of evaporation will increase.True or False

Answer 17

True

Question 18

Mixtures are combinations of materials that can be separated with chemical reactions (T/F)

Answer 18

False: Mixtures are combinations of materials that can be separated by mechanical or physical processes. If the atoms can only be separated with chemical reactions, they are called molecules, not mixtures.

Question 19

When a substance goes from being a solid to a liquid, it is a…Chemical Change
Physical Change

Answer 19

Physical Change

Question 20

If one substance combines with another to make a new compound
Chemical Change
Physical Change

Answer 20

Chemical Change

Question 21

You may find plasma in a star. True or False

Answer 21

True

Question 22

Which of these choices will NOT change the state of matter?
Temperature
Crushing a Crystal
Pressure
Electricity

Answer 22

Crushing a Crystal

Question 23

If you leave water in a glass and some molecules turn into a gas, it is called…

Answer 23

Evaporation

Question 24

Which of these choices is NOT an example of a plasma?-Aurora Borealis
Fluorescent Light Bulb
Neon Sign
Incandescent Light Bulb

Answer 24

Incandescent Light Bulb

Question 25

What is usually the total charge of a plasma? Positive Negative Neutral

Answer 25

Usually, the total charge of plasma is neutral. As the atoms are energized, electrons are released into the system. That release leaves a bunch of positive and negative charges. All of those charges cancel each other out and leave you with plasma that has neutral charge.

Question 26

When a liquid is cooled very quickly, it always forms a crystal.True False

Answer 26

Even though a liquid cools to become a solid, it doesn't always form crystals. Super-quick freezing actually stops all of the random motion found in a liquid. That random assortment of molecules is then apparent in the structure of the solid. If you cool a liquid very slowly, you have a better chance of having the molecules form a specific organization. That organization is the basis of any crystal.

Question 27

``` Amorphous solids… Are more flexible at higher temperatures Include glasses Do not have specific melting points All of the Above ```

Answer 27

All of the above

Question 28

What is an ionic bond?

Answer 28

when a positively charged ion forms a bond with a negatively charged ions and one atom transfers electrons to another

Question 29

What is an ion

Answer 29

an atom or molecule that has an electric charge

Question 30

How does an ion get its charge

Answer 30

gains or looses electrons

Question 31

The strong electrostatic forces of attraction between oppositely charged ions are called

Answer 31

ionic bonds

Question 32

What are the two types ions

Answer 32

Anions and Cations

Question 33

Are Cations positively or negatively charged

Answer 33

positively

Question 34

Are anions positively or negatively charged

Answer 34

negatively

Question 35

Metallic solids called alloys are made of one extremely pure element. T/F

Answer 35

Alloys are combinations of metals and another compound. Some alloys can be made from the mixing of two metals such as copper (Cu) and iron (Fe). Other alloys are made by mixing a metal with a non-metal element. An example of that type of alloy is the extremely strong carbon-steel used in many products

Question 36

``` Which of these is a type of solid? Ionic Metallic Amorphous All are different types of solids. ```

Answer 36

All of them

Question 37

Crystals are disorganised groups of molecules?

Answer 37

Crystals are extremely organized groups of molecules and atoms. Simple crystals are made of one element. Diamonds are great examples of a simple crystal. Other crystals are made of a single element, but have trace amounts of a second element in the crystal lattice. Emeralds are an example of a crystal that has trace amounts of beryllium (Be).

Question 38

all materials move through all three phases as temperatures increase. (True or False)

Answer 38

Not all materials move through all three phases as temperatures increase. Some materials, such as carbon dioxide, can move directly from a solid to a gaseous state of matter. The term used to describe this change of state is "sublimation". You can see it happen whenever you watch dry ice placed in a container of water.

Question 39

What is sublimation

Answer 39

Some materials, such as carbon dioxide, can move directly from a solid to a gaseous state of matter.

Question 40

Forces of attraction in liquids are ___ than in solids. Weaker Stronger About the Same

Answer 40

Forces of attraction in liquids are weaker than the forces of attraction in solids. It might be a complicated term, but it's an easy concept. Think about a block of ice. Try to pull it apart with your hands. The only way to break it apart is to crack it. That effort requires a lot of energy. Now think about a glass of water. Try putting your hand in a bowl of water and taking some water out. Hey! It's easy because the forces of attraction are weaker in the liquid form.

Question 41

It is just as easy to compress a liquid, as it is to compress a gas. (T/F)

Answer 41

False

Question 42

``` All liquids have the same... Density Viscosity Solubility All of the above None of the above ```

Answer 42

None of the above All compounds in a liquid state have different physical properties. Liquids have different densities. That means their molecules are closer together or further apart. Viscosity, or the ability to flow, is also different. Water has a lower viscosity than tree sap. Solubility is the ability of one substance to be dissolved in another. Table salt (NaCl) may be easily dissolved in water, but not as easily in oil.

Question 43

Liquids that move quickly downhill are described as being... High Viscosity Low Viscosity Heavier

Answer 43

Viscosity is a measure of how well fluids flow. You can think of it as friction inside the liquids. If there is a lot of friction (higher viscosity), the fluid will move slower downhill. With less friction (lower viscosity), the fluid can move quickly downhill. Examples of liquids with low viscosity are water and isopropyl alcohol. Highly viscous liquids include tree sap.

Question 44

All liquids can be combined to form solutions (T/F)

Answer 44

False

Question 45

No pure elements are liquids at room temperature T/F

Answer 45

While most of the elements you think of are either gas or solid at room temperature, there are a few exceptions. Mercury (Hg) is the easy answer. You may have seen it in your classes or thermometers. It is always liquid at room temperature. A little less common is the element bromine (Br). These two elements are rare exceptions on the periodic table

Question 46

Evaporation and boiling are the same process, because molecules move from a liquid to a gas state

Answer 46

Evaporation and boiling are much different processes. The process of boiling occurs when the temperature of the entire system reaches a special point. At that point, the energy of the system increases and liquid molecules gain the energy to become a gas. The energy is spread throughout the entire system. The key difference in the two processes is the fact that evaporation can happen on a molecular level at temperatures below the boiling point.

Question 47

Gas molecules are always evenly distributed in the atmosphere.TrueFalse

Answer 47

Many localized areas on the surface of the Earth have gases at different concentrations. Scientists have discovered areas near volcanoes that contain high concentrations of carbon dioxide that can kill living things (even trees). The carbon dioxide collects near the surface because it is heavier than the gases that make up most of the atmosphere.

Question 48

The molecules in a gas are in constant motion. T/F

Answer 48

The molecules in a gas are more active than the molecules found in solids and liquids. Molecules in liquids are also in constant motion, but closer together. Molecules of a solid are often locked into position.