Year 8 Chemistry T3 Flashcards
What is matter?
Everything that takes up space.
What are the three types of matter?
Solid, Liquid, Gas
How much of the Earth is covered by water?
71% of the Earth is covered by water.
How is Earths freshwater stored?
Earth’s freshwater is stored in polar ice caps and glaciers.
How are clouds formed?
a) from water vapor
b) from liquid water turning into water vapor
c) from water vapor turning into liquid water
d) from liquid water
c) from water vapor to liquid water.
When the invisible water vapor in the air cools down, it forms droplets of liquid water that are so tiny that they stay afloat and form clouds.
What is boiling?
A rapid change of state from liquid to gas, with vigorous bubbling.
What is a change of state?
A transition between forms of matter when energy is added or removed
What is the meaning of compressible?
Able to be squeezed into a smaller space.
What is condensation?
A change of state from gas to liquid.
What is deposition?
A change of state from gas to solid.
What is evaporation?
A change of state from liquid to gas at the surface of a liquid
What are the properties of a fluid?
Able to flow and change shape.
What is freezing/solidification?
A change of state from liquid to solid.
What are the properties of gas?
A substance with no fixed shape or volume
What does it mean if a object is incompressable.
Unable to be squeezed into a smaller space.
What are the properties of a liquid?
A substance with a fixed volume that flows and changes shape
What is matter?
State an example of each type of matter.
Any substance that takes up space and has mass
eg. water, ice, water vapor, wood, glass, juice, carbon dioxide, helium.
What is melting?
A change of state from solid to liquid
What is the particle model?
The idea that all matter is made up of tiny particles
What is the mean of rigid.
Unable to bend, flow or change shape
Define a solid.
A substance with a fixed shape and volume
What happens when something solidifies?
It changes from a state from liquid to solid.
What does sublimation mean?
A change of state from solid to gas.
What is water vapor?
Water in its gas state
What is a alkali metal?
A soft, shiny metal that is highly reactive
Alkali metals are located in the first group of the periodic table.
What is an atom?
The smallest particle of an element. An atom is made up of even smaller “subatomic” particles.
What is an atomic number?
The number by which elements are ordered in the periodic table.
e.g. Carbon has the atomic number 6 and is followed in the periodic table by nitrogen (7) and oxygen (8).
What is a boiling point?
The temperature at which a substance changes from liquid to gas
What is the definition of brittle?
Easily broken
Many non-metal elements are brittle, breaking easily when hit.
What is a chemical bond?
An attractive force that holds two atoms together.
Chemical bonds are broken or formed during chemical reactions.
What is a chemical formula?
A symbol that shows the chemical composition of a substance.
The chemical formula for water shows that it has 2 hydrogen atoms for each oxygen atom.
What is a chemical reaction?
The re-arrangement of atoms to form one or more new substances.
Hydrogen and oxygen gases chemically react to form a new substance, water.
What’s a chemical symbol?
One or two letters used to represent an element
What is a compound?
A substance made up of two or more types of atom bonded together
What is an element?
A substance made up of only one type of atom.
How many natural occurring elements are there?
About 90 (94 to be precise)
How many elements have been discovered overall?
118.
What is a group?
A column in the periodic table.
Elements in the same group have similar properties. Atomic number increases from top to bottom.
Define lattices.
A repeating arrangement of atoms in a solid.
What is malleable.
Able to be hammered or pressed into shape without breaking.
What is a melting point?
The temperature at which a substance changes from solid to liquid.
State the properties of matals.
A shiny element that conducts heat and electricity.
What is a mixture?
A combination of substances that can be physically separated because they are not chemically bonded.
What is a molecule?
A group of atoms bonded together.
What are noble gases?
Elements that are highly non-reactive. Found in the last group of the periodic table.
What is a non-metal?
An element that typically does not conduct heat or electricity. Non-metals are located in the top right corner of the periodic table.
What does non-reactive mean?
Tending not to chemically interact with other substances.
Helium is non-reactive. If you place a flame in helium gas, the flame will go out.
What is a period on the periodic table?
A row in the periodic table.
Elements in the same period have different properties. Atomic number increases from left to right.
What is the periodic table?
A grid arrangement of all known chemical elements.
The modern periodic table was developed by Dmitri Mendeleev in the 1860s.
What is a pure substance?
A single substance without anything mixed in
Elements and compounds are pure substances rather than mixtures.
What does reactive mean?
Tending to chemically interact with other substances.
When reactive substances are mixed together, a chemical reaction occurs.
