Comprehensive Science Revision: Heat, Sound, Atomic Structure, Reproduction, Earth Systems

What is the difference between heat and temperature?

Heat is the total kinetic energy of particles in a substance, while temperature measures the average kinetic energy of those particles.

What are the units for heat and temperature?

Heat is measured in joules (J) and temperature in degrees Celsius (°C) or Kelvin (K).

How is heat transferred via conduction in solids?

Heat is transferred through direct contact between particles, where faster-moving particles collide with slower ones, transferring energy.

Why are metals better conductors of heat than other solids?

Metals have delocalised electrons that can move freely, facilitating the transfer of heat.

How is heat transferred via convection in liquids and gases?

Heat causes fluid to expand and become less dense, rising while cooler, denser fluid sinks, creating a convection current.

What is radiation in terms of heat transfer?

Radiation is the transfer of heat through electromagnetic waves, requiring no particles.

What is infrared radiation?

Infrared radiation is a type of electromagnetic wave that is associated with heat.

What is the difference between the wave and particle model of energy transfer?

The wave model describes energy transfer through waves, while the particle model describes it through the movement of particles.

What is a radiation absorber and emitter?

A radiation absorber is a material that takes in radiation, while a radiation emitter is a material that releases radiation. Examples include black surfaces (good absorbers/emitter) and shiny surfaces (poor absorbers/emitter).

What is an insulator and how does it work?

An insulator is a material that reduces heat transfer by limiting the movement of particles. Examples include rubber and glass wool.

What is required for sound to be produced?

Objects must vibrate to produce sound.

How does sound transfer energy?

Sound is a wave that transfers kinetic energy through particle vibrations.

What type of wave is a sound wave?

Sound waves are longitudinal mechanical waves consisting of compressions and rarefactions.

What is frequency in relation to sound?

Frequency (measured in Hertz, Hz) is the number of waves produced per second, which determines the pitch of the sound.

How is loudness measured?

Loudness is measured in decibels (dB) and is related to the amplitude of the sound wave.

What is the atomic number of an atom?

The atomic number is the number of protons in an atom, which determines the element.

What is the mass number of an atom?

The mass number is the total number of protons and neutrons in an atom.

What are ions?

Ions are atoms that have gained or lost electrons, resulting in a positive or negative charge.

What happens during a chemical reaction?

Atoms in the reactants rearrange to form new products, breaking and forming chemical bonds.

What is the Law of Conservation of Mass?

In a chemical reaction, no new atoms are created or destroyed; the total number of atoms remains the same.

What are common types of chemical reactions?

Common reactions include acid-metal, acid-base, acid-metal carbonate, corrosion, and combustion.

What is the role of the central nervous system?

The central nervous system processes information and coordinates responses.

What are the functions of neurons?

Neurons transmit information to and from the central nervous system.

What is homeostasis?

Homeostasis is the maintenance of a stable internal environment in the body.

What is the carbon cycle?

The carbon cycle is the continuous movement of carbon through the atmosphere, hydrosphere, geosphere, and biosphere.

What is photosynthesis?

Photosynthesis is the process by which plants, some bacteria, and algae convert light energy into chemical energy, producing glucose and oxygen.

What is cellular respiration?

Cellular respiration is the process by which living cells convert glucose and oxygen into energy, producing carbon dioxide and water.

What is the difference between complete and incomplete combustion?

Complete combustion occurs with sufficient oxygen, producing carbon dioxide and water, while incomplete combustion occurs with insufficient oxygen, producing carbon monoxide and soot.

What is reproduction in biological terms?

The making of a new offspring via sexual or asexual means.

How does asexual reproduction occur?

It occurs when one individual reproduces itself to form identical offspring through strategies such as binary fission, budding, fragmentation, and parthenogenesis.

In which organisms does asexual reproduction predominantly occur?

In non-flowering plants, protists, and bacteria, but can also occur in some animals.

What is sexual reproduction?

It occurs when two gametes (sex cells) join to create offspring with half the genetic information from each parent.

Where does sexual reproduction mainly occur?

In animals and flowering plants, involving the fertilization of gametes to form offspring.

What are the two types of fertilization in sexual reproduction?

Internal and external fertilization, depending on the environment or habitat.

How are the reproductive strategies of multicellular animals related to their environment?

They are related to the environment and the complexity of the organism.

What is a key difference between sexual and asexual reproduction in terms of variation?

Sexual reproduction creates a greater rate of variation among offspring compared to asexual reproduction.

What is a disadvantage of sexual reproduction compared to asexual reproduction?

Sexual reproduction is slower and more complex.

Can some organisms utilize both sexual and asexual reproductive strategies?

Yes, some organisms, including plants, fungi, and some animals, can utilize both strategies.

What are the four main spheres of the Earth?

Hydrosphere, atmosphere, geosphere, biosphere.

Why is the Earth considered a closed system in relation to matter?

The Earth is considered a closed system because it does not gain or lose significant amounts of matter, apart from a very small amount (e.g., meteorites entering the atmosphere).

What does the carbon cycle represent?

The continual exchange and movement of carbon through the atmosphere, hydrosphere, geosphere, and biosphere.

How do substances like sea shells, wood, plastic, wool, and bubbly water contain carbon atoms?

These substances contain carbon atoms due to biological processes, fossilization, or chemical reactions that incorporate carbon.

Why is photosynthesis a key process in the carbon cycle?

Photosynthesis is crucial because it allows plants, some bacteria, and algae to convert carbon dioxide into organic compounds, thus integrating carbon into the biosphere.

What is cellular respiration and why is it important in the carbon cycle?

Cellular respiration is the process by which all living cells convert organic compounds into energy, releasing carbon dioxide back into the atmosphere.

How are photosynthesis and respiration interrelated?

The products of photosynthesis serve as the reactants for respiration and vice versa, creating a cycle of carbon exchange.

What are the word equations for photosynthesis and respiration?

Photosynthesis: Carbon dioxide + Water → Glucose + Oxygen; Respiration: Glucose + Oxygen → Carbon dioxide + Water.

Where do reactants enter and products leave in photosynthesis?

Reactants (CO2 and H2O) enter through the stomata and roots, while products (glucose and O2) leave through the stomata.

Why is photosynthesis described as an endothermic reaction?

Photosynthesis is endothermic because it absorbs energy from sunlight to convert carbon dioxide and water into glucose.

Why is respiration described as an exothermic reaction?

Respiration is exothermic because it releases energy when glucose is broken down into carbon dioxide and water.

What are stomata and their function in plants?

Stomata are small openings on leaves that allow the exchange of gases (CO2 and O2) between the plant and the atmosphere.

How is carbon from dead organisms returned to the geosphere and atmosphere?

Carbon is returned to the geosphere through lithification and to the atmosphere through decomposition.

How are coal, oil, and natural gas formed?

These fossil fuels are formed from the remains of ancient organisms that underwent heat and pressure over millions of years, incorporating carbon from those organisms.

What is the difference between complete combustion and incomplete combustion?

Complete combustion occurs when there is enough oxygen, producing carbon dioxide and water; incomplete combustion occurs with insufficient oxygen, producing carbon monoxide and soot.

What is the impact of human combustion of hydrocarbons on carbon release?

The combustion of fossil fuels by humans releases carbon atoms from the geosphere into the atmosphere as carbon dioxide.