Science

Question 1

What happens when two sound waves reinforce?

Answer 1

The sound becomes louder.

Question 2

What happens when two sound waves cancel?

Answer 2

No sound is heard.

Question 3

What is amplitude?

Answer 3

The maximum distance that particles move forward or backward in a sound wave.

Question 4

What is frequency?

Answer 4

The number of vibrations per second, measured in Hertz (Hz).

Question 5

What does the collision theory describe?

Answer 5

The formation of the moon through a collision between Earth and a Mars-sized object called Theia.

Question 6

If the collision theory were correct, which objects would contain particles from Theia?

Answer 6

Both the Earth and the Moon.

Question 7

Which planet is closest in size to Theia?

Answer 7

Mars.

Question 8

What is a stellar nursery?

Answer 8

A region where new stars form.

Question 9

What are the most common gases in a nebula?

Answer 9

Hydrogen and Helium.

Question 10

What is conduction?

Answer 10

The transfer of thermal energy in solids.

Question 11

What is convection?

Answer 11

The transfer of thermal energy in liquids and gases.

Question 12

What is radiation?

Answer 12

The transfer of thermal energy without requiring particles (such as heat from the Sun).

Question 13

How do you calculate resistance?

Answer 13

Resistance = Voltage / Current (measured in Ohms, Ω).

Question 14

What happens when resistance increases in a circuit?

Answer 14

The current decreases.

Question 15

What factors will speed up a chemical reaction?

Answer 15

Temperature, Concentration, Surface Area

Question 16

What happens to the rate of reaction when surface area/temperature/concentration increases?

Answer 16

Rate of reaction increases

Question 17

Why does calcium powder react faster than it is in lumps?

Answer 17

Because the surface area is more.

Question 18

What does a steeper line on a reaction graph indicate?

Answer 18

The reaction is fast

Question 19

How does increasing temperature affect the energy of particles?

Answer 19

Heat energy will be converted into kinetic energy in the particles, making them move faster, and collide with each other more.

Question 20

What is dilution?

Answer 20

Less number of particles in a fixed volume, by adding any type of liquid, but typically being water.

Question 21

Name the reactivity series in order.

Answer 21

Potassium, sodium, calcium, magnesium, zinc, iron, copper, silver, gold

Question 22

What product will always come when metal and acid reacts?

Answer 22

Salt + hydrogen

Question 23

What product will always come when metal oxide and acid reacts?

Answer 23

Salt + water

Question 24

What product will always come when metal carbonate and acid reacts?

Answer 24

Salt + water + carbon dioxide

Question 25

What product will always come when metal hydroxide and acid reacts?

Answer 25

Salt + water

Question 26

What is concentration?

Answer 26

It is the amount of substance in a definite volume

Question 27

What is calcium carbonate?

Answer 27

A limestone

Question 28

What is the measurement of thermal energy?

Answer 28

joules

Question 29

What is convection current?

Answer 29

It cause all liquids or gases to heat up eventually

Question 30

What is conduction?

Answer 30

a process where heat transfers through direct contact, without the movement of the material itself.

Question 31

What is the structure of DNA called?

Answer 31

Double Helix.

Question 32

What are the male and female gametes in humans?

Answer 32

Sperm and egg.

Question 33

What causes variation in a species?

Answer 33

Both genetics and the environment.

Question 34

Humans have 23 pairs of chromosomes in their body cells. (True/False)

Answer 34

True.

Question 35

A gene is made up of lipids and carbohydrates. (True/False)

Answer 35

False – It is made of DNA.

Question 36

DNA is found inside the mitochondria. (True/False)

Answer 36

False – It is found in the nucleus.

Question 37

The sperm cell determines the sex of a baby. (True/False)

Answer 37

True – The sperm carries X or Y chromosomes.

Question 38

Environmental factors can influence physical traits. (True/False)

Answer 38

True.

Question 39

All variations in organisms are beneficial. (True/False)

Answer 39

False – Some variations may not provide an advantage.

Question 40

The structure of DNA is a ____________.

Answer 40

Double helix.

Question 41

__________ are sections of DNA that code for specific proteins.

Answer 41

Genes.

Question 42

The ____________ controls the activities of the cell.

Answer 42

Nucleus.

Question 43

Male gametes in humans are called ____________.

Answer 43

Sperm.

Question 44

Female gametes in humans are called ____________.

Answer 44

Egg or ovum.

Question 45

Gametes contain ____________ the number of chromosomes as body cells.

Answer 45

Half.

Question 46

Passing on DNA from parent to offspring is known as ____________.

Answer 46

Inheritance.

Question 47

Variation within a species is caused by ____________ and ____________.

Answer 47

Genetic factors, environmental factors.

Question 48

Eye color is an example of ____________ variation.

Answer 48

Genetic.

Question 49

Organisms that are better adapted to their environment are more likely to ____________.

Answer 49

Survive and reproduce.

Question 50

An organelle that contains chromosomes is ____________.

Answer 50

Nucleus.

Question 51

A type of molecule that carries genetic instructions is ____________.

Answer 51

DNA.

Question 52

The fusion of male and female gametes is called ____________.

Answer 52

Fertilization.

Question 53

The new cell formed when the nucleus of the sperm cell and the egg cell join together is called ____________.

Answer 53

Zygote.

Question 54

The term for differences between individuals belonging to the same species is ____________.

Answer 54

Variation.

Question 55

The process where organisms with advantageous features are more likely to survive and reproduce is called ____________.

Answer 55

Natural Selection.

Question 56

Why is DNA important in living organisms?

Answer 56

DNA carries genetic instructions for the growth, development, reproduction, and survival of organisms.

Question 57

Why do gametes have only half the number of chromosomes?

Answer 57

So that when fertilization occurs, the offspring has the correct number of chromosomes.

Question 58

Why do some species become extinct?

Answer 58

Species that fail to adapt to environmental changes cannot survive or reproduce, leading to extinction.

Question 59

Explain how giraffes evolved to have long necks using natural selection.

Answer 59

Originally, giraffes had different neck lengths. Giraffes with longer necks could reach more food, survived better, and passed this trait to offspring. Over generations, giraffes evolved longer necks.

Question 60

Describe the difference between a chromosome and a gene.

Answer 60

A chromosome is a long thread of DNA. A gene is part of a chromosome that helps control a particular characteristic. Each chromosome contains many genes.