Grade 8: Properties of Materials - Atoms, Elements, and Compounds

Atomic number is the number of protons in an atom, unique for each element, while mass number is the sum of protons and neutrons in the nucleus.

Noble gases have a full outer electron shell, making them very stable.

Ionic bonds are formed when atoms gain or lose electrons to become charged ions, while covalent bonds are formed when atoms share electrons.

As you move down the group, the properties of halogens change, with the color darkening and the elements becoming more reactive.

Protons are positively charged particles in the nucleus of an atom.

Ionic compounds are made from metals and non-metals reacting together, while covalent compounds are made from non-metal atoms sharing electrons.

Heat is the total thermal energy in an object, measured in Joules, while temperature is the average energy of particles in an object, measured in Kelvin, Celsius, Reaumur, or Fahrenheit.

Conduction (in solids), convection (in fluids), and radiation (through electromagnetic waves).

The first shell can hold a maximum of 2 electrons.

Alkali metals produce alkalis when reacting with water.

The total energy in the universe remains constant.

To show the flow of energy through a device or process.

Efficiency = (Useful energy / Total energy) x 100%

Dissipation is when thermal energy moves from a hotter place to a colder place, and the energy spreads out and moves to a colder place.

Through the vibration of particles that are close together in solids.

Kilojoules (kJ)

Convection is the transfer of heat in fluids where particles move around.

Xylem vessels form empty tubes for water transport throughout the plant.

Transpiration is the loss of water vapor from plant leaves. When a plant loses too much water, it becomes wilted, causing leaves and soft tissues to flop over.

The three main functions of water in plants are: 1) Support, 2) Transport, and 3) Cooling.

Folic acid helps reduce the risk of neural tube defects (birth defects of the brain and spinal cord) in the fetus.

Protein is necessary for the fetus to produce new cells and grow.

Carbohydrates supply energy to the fetus.

Iron is essential for producing hemoglobin.

Calcium helps the baby develop strong bones and maintains the mother's bone and teeth health.

It reduces the oxygen transport capacity of hemoglobin, leading to less oxygen for the fetus's cells and impaired growth.

It is a list of metals arranged by their reactivity, from most reactive at the top to least reactive at the bottom.

A more reactive metal displaces a less reactive one from its compound.

It is exothermic, releasing a large amount of heat.

Carbon can displace metals like zinc, iron, tin, and lead from their oxides.

A salt is formed when a metal reacts with an acid.

Metals with hydrochloric acid produce metal chlorides and hydrogen.

The reactivity series can be used to predict whether a metal will react with a metal oxide or a metal sulfate solution by comparing the positions of the metals in the series. A more reactive metal will displace a less reactive metal from its oxide or sulfate solution.

When a metal carbonate reacts with an acid, it produces a salt, water, and carbon dioxide.

The law of conservation of mass states that the mass of reactants equals the mass of products in a chemical reaction. This means that matter cannot be created or destroyed, only transformed.

Conducting displacement reactions with various metals helps to predict and understand how different metals react with metal oxides and metal sulfate solutions based on the reactivity series.

Sound is a form of energy transferred as longitudinal waves, produced by vibrating sources in a medium (solid, liquid, gas).

The main point of studying displacement reactions using the reactivity series is to predict and understand how different metals react with metal oxides and metal sulfate solutions.

The reactivity series is significant in understanding displacement reactions because it allows us to predict which metals will react with metal oxides and metal sulfate solutions.

Understanding neutralization reactions is important because it allows us to understand how acids and bases react to form salts and water.