terms

Atomic mass

How heavy an atom is, like the weight of a tiny piece of building block.

Atomic number

A special number that tells you how many little balls (protons) are inside an atom.

Atomic radius

How big an atom is from the center to the edge, like the size of a tiny balloon.

Bohr-Rutherford diagrams

Pictures that show how the bits of an atom fit together, like a drawing of a family.

Boiling Point

The temperature when water gets so hot, it turns into steam, like when you see bubbles in a pot of boiling water.

Carbon dioxide test

A way to see if there’s a special gas that we breathe out, like blowing up a balloon.

Catalyst

A helper that makes something happen faster, like a friend pushing you on a swing.

Chemical changes

Changes that make something completely new, like when mixing paint to make a different color.

Chemical properties

Traits that tell us how a substance can change when it reacts, like how baking soda makes things bubble when mixed with vinegar.

Compounds

Things made of two or more different types of building blocks stuck together, like making a sandwich.

Concentration

How much of something is in a liquid, like how strong lemonade tastes if you add more sugar.

Condensation

The way water droplets form on a cold surface, like when you see dew on grass in the morning.

Conductivity

How well something can let electricity pass through, like how metal can carry electricity to light up your room.

Covalent bonds

When two atoms stick together by sharing things, like best friends sharing toys.

Density

How heavy something is compared to how much space it takes up, like the difference between a balloon and a rock.

Deposition

The process of gas turning into a solid, like frost forming on a chilly morning.

Ductility

How much you can stretch a material without breaking it, like stretching a piece of silly putty.

Electron

Tiny particles that are part of an atom, like little dots buzzing around a toy.

Elements

Basic building blocks of everything around us, like single colors of paint.

Ernest Rutherford

A scientist who helped us understand atoms better, like a detective figuring out a mystery.

Evaporation

When water turns into vapor and disappears, like magic disappearing water.

Gas

A type of matter that is light and spreads out, like the air you breathe.

Gold foil experiment

A test where tiny particles were shot at gold to discover the atom's center, like throwing balls at a castle to see what happens.

Group (periodic table)

A column of similar elements in a chart, like a family of animals that are all alike.

Hardness

How tough a material is; how easily it can be scratched, like how hard a rock is compared to a piece of chalk.

Heterogeneous mixture

A mix where you can see different parts, like a salad with different vegetables inside.

Homogeneous mixture

A mix that looks the same everywhere, like a smoothie where everything is pureed together.

Hydrogen test

A way to check for hydrogen gas, like seeing sparks when you light a firecracker.

Indicator of chemical change

A sign that something new has been made, like changing colors in a science experiment.

Ionic bonds

Bonds where one atom gives away a part to another, like sharing a cookie where you get half and your friend gets the other half.

J. J. Thomson

A scientist who discovered what tiny atoms are made of, like finding out what’s inside a toy.

John Dalton

A scientist who figured out atoms are like tiny balls, like building blocks.

Liquid

A state of matter that can flow and take the shape of its container, like water in a cup.

Lustre

How shiny or dull something looks, like a shiny apple versus a matte rock.

Malleability

How easily something can be shaped, like squishing playdough.

Matter

Anything that takes up space and has weight, like your toys or your body.

Melting

When something turns from solid to liquid, like ice turning to water.

Melting Point

The temperature when ice turns into water, like when the sun makes your ice cream drip.

Mixtures

Combines different things without changing them permanently, like making a fruit salad.

Naming ionic compounds

Finding a special name for things made from atoms that like to stick together, like naming your pet.

Naming molecular compounds

Giving names to things made from non-metal atoms, just like naming your favorite food.

Neutron

Tiny neutral particles that help make up the center of an atom, like the glue holding it together.

Niels Bohr

A scientist who helped us picture how electrons circle around an atom, like planets around the sun.

Nucleus

The center part of an atom, like the yolk of an egg where everything is stored.

Orbital

The space around the nucleus where we find electrons, like the area where a story character moves.

Oxygen test

A way to find out if there is oxygen, like how a candle glows brighter with extra air.

Particle theory

The idea that everything is made of tiny pieces that are always moving, like how kids are always bouncing around.

Periodic (periodic table)

A special chart that shows all the different kinds of elements, like a big box of crayons with different colors.

Periodic table trends

Patterns we see in the properties of elements, like how some animals can fly and some can’t.

Physical changes

Changes that don’t turn things into something new, like cutting paper into smaller pieces.

Physical properties

Traits we can see or touch without changing them, like the color of a toy.

Product

The result of a magical mixing process, like cookies coming out of the oven.

Proton

A positively charged particle found in the nucleus of an atom, like a friendly ball in the center.

Pure substances

Things made up of just one type of material, like a spoonful of sugar.

Reactant

Things used up during a change, like ingredients you need to bake a cake.

Solidification

When a liquid turns back into solid, like ice forming in a freezer.

Solubility

How easily something dissolves in water, like how sugar disappears in your drink.

Solution

A mix where one thing is dissolved in another, like making lemonade.

Solute

The stuff you mix into a liquid, like the sugar you put into lemonade.

Solvent

The liquid that does the dissolving in a solution, like water in lemonade.

States of matter

The different forms things can take, like ice, water, or steam.

Sublimation

When a solid turns straight into a gas, like dry ice disappearing into air.

Viscosity

How thick a liquid is, like syrup being thicker than water.

Water vapour test

A way to see if there’s water vapor, like seeing steam rising from hot soup.