Science at4 deck 1

Question 1

Describe the physical signs that indicate a chemical reaction has occurred.

Answer 1

Physical signs include colour change, temperature change, formation of bubbles or gas, odour change, and the formation of a precipitate.

Question 2

Define precipitate in the context of a chemical reaction.

Answer 2

A precipitate is a solid that forms when two liquids react and produce an insoluble compound, settling out of the solution.

Question 3

How does temperature change relate to chemical reactions?

Answer 3

Temperature change indicates whether a reaction is exothermic (releases energy) or endothermic (absorbs energy), causing the temperature to increase or decrease.

Question 4

Explain the significance of gas bubble formation in chemical reactions.

Answer 4

The production of gas bubbles is a common indicator that a chemical reaction has taken place.

Question 5

What happens during the synthesis reaction of hydrogen and oxygen?

Answer 5

In a synthesis reaction, hydrogen gas (H2) and oxygen gas (O2) combine to form water (H2O), creating a new compound.

Question 6

Describe the process of electrolysis in breaking down water.

Answer 6

Electrolysis involves applying an electric current to water (H2O), breaking it down into hydrogen (H2) and oxygen (O2) gases.

Question 7

Construct the word equation for photosynthesis.

Answer 7

Carbon dioxide + water = Glucose + oxygen.

Question 8

What is the chemical equation for cellular respiration?

Answer 8

C6H12O6 + 6O2 → 6CO2 + 6H2O + Energy (ATP).

Question 9

Identify the products of the combustion of methane.

Answer 9

The combustion of methane produces carbon dioxide, water, and energy (ATP). The chemical equation is CH4 + 2O2 → CO2 + 2H2O + Energy.

Question 10

Propose reasons for supporting scientific research into new substances.

Answer 10

Reasons include innovation and growth, health advancements, environmental sustainability, and the expansion of scientific knowledge.

Question 11

Define energy in the context of work.

Answer 11

Energy is the ability or capacity to do work, and it can change from one form to another.

Question 12

What is kinetic energy and provide examples of its forms.

Answer 12

Kinetic energy is the energy of motion, with examples including mechanical energy, heat, light, sound, and current electricity.

Question 13

Describe mechanical energy.

Answer 13

Mechanical energy is the sum of kinetic and potential energy in an object, representing the energy associated with the motion and position of that object.

Question 14

Define light energy.

Answer 14

Light energy is energy that travels in waves and is visible to the human eye, which is a form of electromagnetic radiation.

Question 15

How is thermal energy defined?

Answer 15

Thermal energy is the total kinetic energy of the particles in a substance due to their motion, arising from the temperature of the object.

Question 16

Explain sound energy.

Answer 16

Sound energy is produced by vibrating objects and is transmitted through a medium as sound waves.

Question 17

What causes electrical energy?

Answer 17

Electrical energy is caused by the movement of electrons through a conductor and can be converted to other forms of energy.

Question 18

Identify examples of potential energy.

Answer 18

Examples of potential energy include gravitational, chemical, elastic, nuclear, and static electricity.

Question 19

Describe gravitational energy.

Answer 19

Gravitational energy is the energy stored in an object due to its height above the ground and the gravitational force acting on it.

Question 20

What is chemical energy?

Answer 20

Chemical energy is the energy stored in the bonds of chemical compounds, which can be released during a chemical reaction.

Question 21

Define elastic energy.

Answer 21

Elastic energy is stored in objects that can be stretched or compressed, such as springs and elastic materials.

Question 22

Explain nuclear energy.

Answer 22

Nuclear energy is stored in the nucleus of an atom, related to the forces that hold protons and neutrons together.

Question 23

What is static electricity?

Answer 23

Static electricity is energy stored due to the position of charged particles in an electric field.

Question 24

Distinguish between energy transfers and energy transformations.

Answer 24

Energy transfers refer to the movement of energy from one location or object to another without changing its form, while energy transformations involve changing energy from one form to another.

Question 25

Describe the process of photosynthesis in terms of energy transformation.

Answer 25

In photosynthesis, plants convert solar energy into chemical energy.

Question 26

How do solar panels work in terms of energy transformation?

Answer 26

Solar panels absorb the sun’s rays and convert solar energy into electrical energy.

Question 27

Outline processes that cause objects to emit heat energy.

Answer 27

Processes that cause objects to emit heat energy include chemical reactions, nuclear reactions, friction, and electricity through wires.

Question 28

What happens during chemical reactions in terms of energy?

Answer 28

Chemical reactions involve breaking and forming bonds between atoms, which can release or absorb energy, with exothermic reactions releasing energy as heat.

Question 29

Define exothermic reactions.

Answer 29

Exothermic reactions are chemical reactions that release energy.

Question 30

Explain nuclear reactions and their energy implications.

Answer 30

Nuclear reactions involve changes in an atom’s nucleus, leading to the release of energy.

Question 31

Describe binary fission and fusion in terms of energy conversion.

Answer 31

Both binary fission and fusion are processes that convert mass into energy, primarily producing heat as a byproduct.

Question 32

How does friction generate heat energy?

Answer 32

Friction occurs when two surfaces rub against each other, converting kinetic energy into thermal energy, such as when rubbing hands together or using brakes.

Question 33

Define the role of resistance in electricity flowing through wires.

Answer 33

Resistance in conductive materials generates heat when an electric current flows through wires, converting electrical energy into heat energy.

Question 34

Explain the inefficiency of electric light bulbs.

Answer 34

Electric light bulbs often have a large percentage of inefficiency, where electrical energy is transformed into heat rather than light.

Question 35

Discuss the impact of inefficient energy transformations on refrigerators.

Answer 35

Refrigerators use electrical energy to remove heat from the interior, leading to energy loss due to the inefficiency of the compressor and its components.

Question 36

How can making energy-transforming technologies more efficient benefit society?

Answer 36

Increased efficiency in energy-transforming technologies reduces energy consumption and lowers greenhouse gas emissions, helping to mitigate climate change and protect ecosystems.

Question 37

Research ways in which energy-transforming technologies have improved efficiency.

Answer 37

Modern buildings are insulated to reduce energy loss, and lighting technologies have evolved from incandescent bulbs to LEDs, which waste less electricity and have longer lifespans.

Question 38

Relate heat energy changes to particle movement during melting.

Answer 38

During melting, heat energy is absorbed by a solid substance, causing it to transition from solid to liquid as particle movement increases.

Question 39

Explain the process of evaporation in terms of heat energy and particle movement.

Answer 39

Evaporation is the transition from liquid to gas, where heat energy is absorbed by the liquid, increasing particle movement.

Question 40

Describe condensation and its effect on heat energy.

Answer 40

Condensation is the transition from gas to liquid, where heat energy is released by the gas, causing particles to move closer together.

Question 41

What happens to heat energy during freezing?

Answer 41

During freezing, heat energy is released by the liquid as it transitions to a solid state, resulting in decreased particle movement.

Question 42

How do changes in heat energy affect the states of matter?

Answer 42

The state of a substance is determined by the balance of heat energy and the forces of attraction between particles, influencing whether it is solid, liquid, or gas.

Question 43

Describe the process of conduction in heat transfer.

Answer 43

Conduction is the transfer of heat through direct contact between materials, where heat moves from the hotter object to the cooler one through the vibration and collision of particles.

Question 44

Give an example of convection and explain the process.

Answer 44

An example of convection is boiling water. As the water is heated, it becomes less dense and rises, while the cooler water moves to the bottom, creating a convection current.

Question 45

Define radiation in the context of heat transfer.

Answer 45

Radiation is the transfer of heat energy through electromagnetic waves, which does not require a medium and can occur in a vacuum, such as sunlight or warmth from a campfire.

Question 46

How does increasing energy conversion efficiency impact society and the environment?

Answer 46

Increasing the efficiency of energy conversions and reducing wasted energy can lead to significant benefits for society and the environment, including reduced energy costs and lower environmental impact.

Question 47

Apply the concept of energy transfer to a solar powered water heater.

Answer 47

In a solar powered water heater, solar energy is transferred to thermal energy, which is then transferred to the water, heating it up.

Question 48

Outline the composition of atoms and their subatomic particles.

Answer 48

Atoms are composed of three subatomic particles: electrons (negatively charged), protons (positively charged and located in the nucleus), and neutrons (no charge). The number of protons is equal to the number of electrons.

Question 49

Explain how batteries provide energy to electrons.

Answer 49

Batteries store chemical energy that can be converted into electrical energy. They consist of two electrodes and an electrolyte, and the process involves the movement of a magnetic field, inducing electromotive force, and energy transfer.

Question 50

Construct a simple circuit and identify its components.

Answer 50

A simple circuit can include a battery, power supply, wires, a switch, a light globe, and a motor, demonstrating that electricity can be transferred and transformed.

Question 51

Identify the internal layers of the Earth.

Answer 51

The internal layers of the Earth include the inner core, outer core, mantle, and crust.

Question 52

Define minerals and their criteria for classification.

Answer 52

Minerals are naturally occurring solid substances with a definite chemical composition. To be classified as a mineral, a substance must occur naturally in the Earth’s crust and meet five specific criteria.

Question 53

Define a mineral.

Answer 53

A mineral is an inorganic solid made from materials that were never living things, with a definite chemical composition and a crystal structure.

Question 54

Describe the characteristics that distinguish minerals from other substances.

Answer 54

Minerals are inorganic, solid, have a definite chemical composition, and their atoms are arranged in a repeating pattern called a crystal.

Question 55

How are minerals related to rocks?

Answer 55

Minerals are the building blocks of rocks, and the types and proportions of minerals present determine a rock’s properties, appearance, and classification.

Question 56

List the three types of rocks.

Answer 56

The three types of rocks are igneous, sedimentary, and metamorphic.

Question 57

Explain the role of convection currents in the Earth’s mantle.

Answer 57

Convection currents in the Earth’s mantle are caused by heat from the core, causing less dense rock to rise and cooler rock to sink, creating circular movements that drive tectonic plate movement.

Question 58

How do convection currents contribute to volcanic eruptions?

Answer 58

Convection currents move tectonic plates, which can create cracks or collisions, allowing magma from the mantle to be pushed up through these cracks and erupt from volcanoes.

Question 59

Describe the process of how igneous rocks are formed.

Answer 59

Igneous rocks are formed from cooled magma that originates from the mantle, with their characteristics influenced by cooling rates, chemical composition, and gas bubbles.

Question 60

Explain the differences in igneous rocks such as basalt, gabbro, obsidian, granite, and pumice.

Answer 60

Differences in igneous rocks arise from variations in chemical composition, cooling rates, and the amount of gas bubbles present during formation.

Question 61

What is the significance of the Earth’s crust being primarily composed of igneous rocks?

Answer 61

The majority of the Earth’s crust is made up of igneous rocks, which are formed from cooled magma, indicating the geological processes that shape the planet.

Question 62

Define the term ‘crystal’ in relation to minerals.

Answer 62

A crystal is a repeating pattern of atoms arranged in a definite structure, characteristic of minerals.

Question 63

How does the cooling rate of magma affect the type of igneous rock formed?

Answer 63

The cooling rate of magma affects the size of the crystals formed; slower cooling allows for larger crystals, while rapid cooling results in smaller crystals or a glassy texture.

Question 64

What is the relationship between gas bubbles and the texture of igneous rocks?

Answer 64

The amount of gas bubbles in magma influences the texture of igneous rocks; more gas bubbles can lead to a lighter, porous texture like pumice, while fewer bubbles can result in denser rocks like granite.