grade 10 exam topics

Chemistry: Reactants and Products

Reactants are the starting substances in a chemical reaction, while products are the new substances formed as a result of the reaction.

Law of Conservation of Mass

States that mass is neither created nor destroyed in a chemical reaction; therefore, \text{Total Mass of Reactants} = \text{Total Mass of Products}.

Bohr Models

A diagram representing an atom that shows the nucleus and the arrangement of electrons in specific energy levels or shells surrounding it.

Valence Electrons

The electrons located in the outermost shell of an atom, which determine the element's chemical reactivity and bonding properties.

Ionic Bonding

A type of chemical bond formed through the transfer of electrons from a metal atom to a non-metal atom, resulting in electrostatic attraction between ions.

Covalent Bonds

Chemical bonds formed when two or more non-metal atoms share pairs of valence electrons to achieve a stable electron configuration.

Physics: Position and Time

Position is the location of an object relative to a reference point, while Time is the interval or duration in which a change or motion occurs.

Distance vs. Displacement

• Distance: The total length of the path traveled by an object (scalar).

• Displacement: The straight-line change in position from the starting point to the ending point, including direction (vector).

Naming Binary Ionic Compounds

Named by writing the name of the metal first, followed by the non-metal with the suffix changed to -ide (e.g., Sodium Chloride).

Molecular Compounds Prefixes

Numerical prefixes used to indicate the number of atoms in a covalent compound:

• 1: mono-

• 2: di-

• 3: tri-

• 4: tetra-

• 5: penta-

Valence Electrons

The electrons located in the outermost shell of an atom, which determine the element's chemical reactivity and bonding properties.

Ionic vs. Molecular Compounds

• Ionic: Formed by electron transfer between metals and non-metals; usually solids with high melting points.

• Molecular (Covalent): Formed by electron sharing between non-metals; can be solids, liquids, or gases with lower melting points.

Covalent Bonds: Single, Double, Triple

• Single Bond: Shares 1 pair of electrons.

• Double Bond: Shares 2 pairs of electrons.

• Triple Bond: Shares 3 pairs of electrons.

Physics: Position and Time

Position is the location of an object relative to a reference point, while Time is the interval or duration in which a change or motion occurs.

Distance vs. Displacement

• Distance: The total length of the path traveled by an object (scalar).

• Displacement: The straight-line change in position from the starting point to the ending point, including direction (vector).

Speed vs. Velocity

• Speed: The rate at which an object covers distance (scalar, v = d/t).

• Velocity: Speed in a specific direction (vector, displacement over time).

Acceleration

The rate at which an object changes its velocity over time, calculated as \text{a} = \frac{\Delta v}{\Delta t}.

Newton's Three Laws of Motion

1. Inertia: An object remains at rest or in motion unless acted on by a net force.

2. F=ma: The force acting on an object is equal to its mass times its acceleration.

3. Action-Reaction: For every action, there is an equal and opposite reaction.

Force and the Newton (N)

A Force is a push or pull. It is measured in Newtons (N), where 1 N = 1 kg \cdot m/s^2.

Pressure

Defined as force acting on a unit area. It is calculated using the formula: P = \frac{F}{A}. Standard unit is the Pascal (Pa).

Pressure in States of Matter

Solids, liquids, and gases all exert pressure. In fluids, pressure is affected by factors such as density, gravity, depth/height, and temperature.

Earth and Space Science: Ozone (O_3)

A molecule composed of three oxygen atoms. It forms the ozone layer in the stratosphere, which protects life on Earth by absorbing harmful ultraviolet (UV) radiation.

Ionic vs. Molecular Compounds

• Ionic: Formed by electron transfer between metals and non-metals; usually solids with high melting points.

• Molecular (Covalent): Formed by electron sharing between non-metals; can be solids, liquids, or gases with lower melting points.

Properties of Solids, Liquids, and Gases

• Solids: Definite shape and volume; particles vibrate in fixed positions.

• Liquids: Definite volume but take the shape of their container; particles move past each other.

• Gases: No definite shape or volume; particles move rapidly and independently.

Systematic Naming of Compounds

IUPAC naming ensures global consistency. Binary Ionic Compounds use the metal name followed by the non-metal with an -ide suffix. Molecular Compounds use numerical prefixes (e.g., mono-, di-, tri-).

Physics: Position and Time

Position is the location of an object relative to a reference point, while Time is the interval or duration in which a change or motion occurs.

Distance vs. Displacement

• Distance: The total length of the path traveled by an object (scalar).

• Displacement: The straight-line change in position from the starting point to the ending point, including direction (vector).

Speed vs. Velocity

• Speed: The rate at which an object covers distance (scalar, v = d/t).

• Velocity: Speed in a specific direction (vector, displacement over time).

Acceleration

The rate at which an object changes its velocity over time, calculated as a = \frac{\Delta v}{\Delta t}.

Newton's Three Laws of Motion

1. Inertia: An object remains at rest or in motion unless acted on by a net force.

2. F = ma: The force acting on an object is equal to its mass times its acceleration.

3. Action-Reaction: For every action, there is an equal and opposite reaction.

Force and the Newton (N)

A Force is a push or pull measured in Newtons (N), where 1 N = 1 kg \cdot m/s^2. Force is a vector quantity.

Pressure (P)

Defined as force acting on a unit area (P = F/A). The standard unit is the Pascal (Pa).

Pressure in States of Matter

All states exert pressure. In fluids, pressure is affected by density, gravity, depth, and temperature.

Ozone (O_3): Composition and Formation

Ozone is a molecule made of 3 oxygen atoms. It forms in the stratosphere when ultraviolet (UV) radiation splits O_2 into free oxygen atoms that then bond with other oxygen molecules.

Ozone Layer and UV Radiation

The ozone layer blocks harmful ultraviolet (UV) radiation from the sun, protecting life on Earth from skin cancer and ecological damage.

Ozone Depletion: CFCs and the Ozone Hole

Chlorofluorocarbons (CFCs) break down ozone. An Ozone Hole is a region where the ozone layer has become exceptionally thin, primarily over Antarctica.

The Montreal Protocol

An international environmental treaty designed to phase out the production of ozone-depleting substances like CFCs. Global cooperation has successfully reduced ozone damage.

Factors Influencing Earth's Climate

• Latitude: Determines the intensity of solar energy.

• Landscape: Mountains affect precipitation and wind.

• Ocean Currents & Winds: Distribute heat globally.

The Coriolis Effect

The apparent deflection of winds and ocean currents to the right in the Northern Hemisphere and left in the Southern Hemisphere due to Earth's rotation.

The Greenhouse Effect

The natural process where gases (like CO_2 and Methane) trap heat in the atmosphere. Human activities, specifically burning fossil fuels, intensify this effect.

Consequences of Climate Change

• Extreme weather and wildfires

• Melting polar ice and rising sea levels

• Ocean acidification

• Flooding and desertification

Natural Resources: Definition and Types

Materials from nature used by society. Includes fossil fuels (coal, oil), ores, minerals, and metals. They are extracted via mining or drilling.

Astronomical Units of Distance

• AU: Distance from Earth to Sun (1.5 \times 10^8 \text{ km}).

• Light Year: Distance light travels in a year.

• Parsec: Approximately 3.26 light years.

Evidence for the Big Bang Theory

Supported by the Cosmic Microwave Background Radiation (CMBR) and the observed Redshift (Doppler shift) of distant galaxies.

Doppler Shift

A change in wavelength of light due to motion. Redshift indicates galaxies are moving away, proving the universe is expanding.

Solar System Formation: Gravity and Accretion

Gravity collapsed a nebula into a disk. Accretion is the process where dust and gas particles clumped together to form planets.

Ages: Universe, Solar System, and Earth

• Universe: Approximately 13.8 billion years.
• Solar System and Earth: Approximately 4.5 billion years.

Stars: Formation and Energy

Stars form in nebulae when gravity collapses gas until Nuclear Fusion begins. Fusion converts Hydrogen into Helium, releasing massive energy.

Types of Stars

Stars are classified by mass and temperature; common types include Average stars (like the Sun), Red Giants, White Dwarfs, and Neutron Stars.

Gravity and Celestial Objects

Gravity is the fundamental force that keeps planets and moons in orbit, governs the motion of galaxies, and drives the life cycle of stars.

Meteor Activity

• Meteoroid: A small rocky body in space.

• Meteor: The streak of light in the atmosphere.

• Meteorite: A rock that survives atmosphere entry and hits the ground.

Life Beyond Earth

No scientific evidence of life has been found beyond Earth yet, primarily due to extreme planetary environments and the vast distances between stars.

Chemistry: Reactants and Products

Reactants are the starting substances in a chemical reaction, while products are the new substances formed as a result of the reaction.

Law of Conservation of Mass

States that mass is neither created nor destroyed in a chemical reaction; therefore, \text{Total Mass of Reactants} = \text{Total Mass of Products}.

Bohr Models

A diagram representing an atom that shows the nucleus and the arrangement of electrons in specific energy levels or shells surrounding it.

Valence Electrons

The electrons located in the outermost shell of an atom, which determine the element's chemical reactivity and bonding properties.

Ionic Bonding

A type of chemical bond formed through the transfer of electrons from a metal atom to a non-metal atom, resulting in electrostatic attraction between ions.

Covalent Bonds

Chemical bonds formed when two or more non-metal atoms share pairs of valence electrons to achieve a stable electron configuration.

Physics: Position and Time

Position is the location of an object relative to a reference point, while Time is the interval or duration in which a change or motion occurs.

Distance vs. Displacement

• Distance: The total length of the path traveled by an object (scalar).

• Displacement: The straight-line change in position from the starting point to the ending point, including direction (vector).

Naming Binary Ionic Compounds

Named by writing the name of the metal first, followed by the non-metal with the suffix changed to -ide (e.g., Sodium Chloride).

Molecular Compounds Prefixes

Numerical prefixes used to indicate the number of atoms in a covalent compound:

• 1: mono-

• 2: di-

• 3: tri-

• 4: tetra-

• 5: penta-

Ionic vs. Molecular Compounds

• Ionic: Formed by electron transfer between metals and non-metals; usually solids with high melting points.

• Molecular (Covalent): Formed by electron sharing between non-metals; can be solids, liquids, or gases with lower melting points.

Covalent Bonds: Single, Double, Triple

• Single Bond: Shares 1 pair of electrons.

• Double Bond: Shares 2 pairs of electrons.

• Triple Bond: Shares 3 pairs of electrons.

Speed vs. Velocity

• Speed: The rate at which an object covers distance (scalar, v = d/t).
• Velocity: Speed in a specific direction (vector, displacement over time).

Acceleration

The rate at which an object changes its velocity over time, calculated as a = \frac{\Delta v}{\Delta t}.

Newton's Three Laws of Motion

1. Inertia: An object remains at rest or in motion unless acted on by a net force.

2. F = ma: The force acting on an object is equal to its mass times its acceleration.

3. Action-Reaction: For every action, there is an equal and opposite reaction.

Force and the Newton (N)

A Force is a push or pull measured in Newtons (N), where 1 N = 1 kg \cdot m/s^2. Force is a vector quantity.

Pressure (P)

Defined as force acting on a unit area (P = F/A). The standard unit is the Pascal (Pa).

Pressure in States of Matter

All states exert pressure. In fluids, pressure is affected by density, gravity, depth, and temperature.

Earth and Space Science: Ozone (O_3)

A molecule composed of three oxygen atoms. It forms the ozone layer in the stratosphere, which protects life on Earth by absorbing harmful ultraviolet (UV) radiation.

Properties of Solids, Liquids, and Gases

• Solids: Definite shape and volume; particles vibrate in fixed positions.

• Liquids: Definite volume but take the shape of their container; particles move past each other.

• Gases: No definite shape or volume; particles move rapidly and independently.

Systematic Naming of Compounds

IUPAC naming ensures global consistency. Binary Ionic Compounds use the metal name followed by the non-metal with an -ide suffix. Molecular Compounds use numerical prefixes (e.g., mono-, di-, tri-).

Ozone (O_3): Composition and Formation

Ozone is a molecule made of 3 oxygen atoms. It forms in the stratosphere when ultraviolet (UV) radiation splits O_2 into free oxygen atoms that then bond with other oxygen molecules.

Ozone Layer and UV Radiation

The ozone layer blocks harmful ultraviolet (UV) radiation from the sun, protecting life on Earth from skin cancer and ecological damage.

Ozone Depletion: CFCs and the Ozone Hole

Chlorofluorocarbons (CFCs) break down ozone. An Ozone Hole is a region where the ozone layer has become exceptionally thin, primarily over Antarctica.

The Montreal Protocol

An international environmental treaty designed to phase out the production of ozone-depleting substances like CFCs. Global cooperation has successfully reduced ozone damage.

Factors Influencing Earth's Climate

• Latitude: Determines the intensity of solar energy.

• Landscape: Mountains affect precipitation and wind.

• Ocean Currents & Winds: Distribute heat globally.

The Coriolis Effect

The apparent deflection of winds and ocean currents to the right in the Northern Hemisphere and left in the Southern Hemisphere due to Earth's rotation.

The Greenhouse Effect

The natural process where gases (like CO_2 and Methane) trap heat in the atmosphere. Human activities, specifically burning fossil fuels, intensify this effect.

Consequences of Climate Change

• Extreme weather and wildfires
• Melting polar ice and rising sea levels
• Ocean acidification
• Flooding and desertification

Natural Resources: Definition and Types

Materials from nature used by society. Includes fossil fuels (coal, oil), ores, minerals, and metals. They are extracted via mining or drilling.

Astronomical Units of Distance

• AU: Distance from Earth to Sun (1.5 \times 10^8 \text{ km}).
• Light Year: Distance light travels in a year.
• Parsec: Approximately 3.26 light years.

Evidence for the Big Bang Theory

Supported by the Cosmic Microwave Background Radiation (CMBR) and the observed Redshift (Doppler shift) of distant galaxies.

Doppler Shift

A change in wavelength of light due to motion. Redshift indicates galaxies are moving away, proving the universe is expanding.

Solar System Formation: Gravity and Accretion

Gravity collapsed a nebula into a disk. Accretion is the process where dust and gas particles clumped together to form planets.

Ages: Universe, Solar System, and Earth

• Universe: Approximately 13.8 billion years.
• Solar System and Earth: Approximately 4.5 billion years.

Stars: Formation and Energy

Stars form in nebulae when gravity collapses gas until Nuclear Fusion begins. Fusion converts Hydrogen into Helium, releasing massive energy.

Types of Stars

Stars are classified by mass and temperature; common types include Average stars (like the Sun), Red Giants, White Dwarfs, and Neutron Stars.

Gravity and Celestial Objects

Gravity is the fundamental force that keeps planets and moons in orbit, governs the motion of galaxies, and drives the life cycle of stars.

Meteor Activity

• Meteoroid: A small rocky body in space.
• Meteor: The streak of light in the atmosphere.
• Meteorite: A rock that survives atmosphere entry and hits the ground.

Life Beyond Earth

No scientific evidence of life has been found beyond Earth yet, primarily due to extreme planetary environments and the vast distances between stars.

Ecology: Ecosystems and Biodiversity

• Ecosystem: A biological community of interacting organisms and their physical environment.
• Biodiversity: The variety of all living things and their interactions in a habitat.

Ecological Hierarchy

The levels of biological organization in ecology:

1. Individual: A single organism.
2. Population: A group of individuals of the same species in an area.
3. Community: All populations of different species in an area.
4. Ecosystem: Community plus abiotic factors.
5. Biome: Large regional ecosystem (e.g., Tundra).
6. Biosphere: All ecosystems on Earth.

Food Webs and Ecological Pyramids

• Food Web: Interconnecting food chains showing complex energy flows.
• Ecological Pyramid: Models showing the amount of energy, biomass, or number of organisms at each trophic level; only about 10\% of energy is transferred up.

Trophic Levels

Steps in a food chain or web (Producers, Primary Consumers, Secondary Consumers, Tertiary Consumers).

Niche and Competition

A niche is a species' unique role and use of resources. Different niches allow species to coexist by reducing direct competition for the same resources.

Biotic vs. Abiotic Factors

• Biotic: Living parts of an ecosystem (e.g., predators, prey, plants).
• Abiotic: Non-living parts (e.g., sunlight, temperature, water, soil minerals).

Carbon and Nitrogen Cycles

• Carbon Cycle: Cycles through photosynthesis, respiration, decomposition, and combustion.
• Nitrogen Cycle: Cycles through nitrogen fixation (by bacteria/lightning), nitrification, and denitrification.

Carrying Capacity and Limiting Factors

• Carrying Capacity: The maximum population an ecosystem can support long-term.
• Limiting Factor: A resource or condition that limits population growth (e.g., food, space, disease).