U2 Evolution of the atom + atomic world

What is matter

Matter is any substance that has a volume (takes up space) and has a mass (g, kg)

What is matter made of?

All matter is made of atoms which can bond together to produce different substances

Everything is either a:

Matter or energy

The relationship between matter and energy can be described as?

Energy changes matter and matter changes energy

What is an atom?

Is the building block of matter made of subatomic particles such as protons, neutrons, and electrons. It is the smallest particle of an element

What was the first atomic theory?

In 1802, John Dalton presented the first theory that all matter is made tiny round particles which are indivisible and indestructible.

Why was John Dalton’s theory wrong?

John Dalton was wrong because atoms are in fact made of smaller subatomic particles, protons, neutrons and electrons.

What are the two groups matter can be spilt into?

Pure substance and Mixture

What is a mixture

Consists of two or more different types particles (eg. elements, compounds) that are not chemically bonded together, and are just floating around not bonded to each other.

What are the two types of mixtures

Homogeneous and heterogeneous

What is a homogenous mixture

Is a type of mixture where the components are evenly distributed and appear uniform (look the same) throughout, the components remain the same wherever you check.

eg, air, salt water

What is the composition of something?

The composition is how something is made up, like the kinds of atoms and molecules in the substance.

What is a heterogeneous mixture?

Is a type of mixture where the components are not evenly distributed and aren’t uniform (don’t look the same), you can see the different parts. The composition changes based off of where you check.

eg. oil and water, sand and gravel.

In what ways can a mixture be seperated?

A mixture can be separated by chemical and physical means. eg. filtration

What is a pure substance?

It’s made up of only one type of particle (element or compound), it has a fixed composition and consistent properties wherever you check. The particles can be made the same or different elements, but it must consist of the same particle.

What are the two types of pure substances?

Elements and compounds.

What is an element?

Types of atoms that share the same amount of protons. In substances this means that they are made up of one or more of the same type of atom.

What can elements exist as?

Elements can be monatomic (just existing as a singular atom, only elements can be monatomic) or polyatomic (existing as two or more of the same atoms chemically (covalently) bonded together). Regardless of its form an element can only be made up of one type of atom. eg. O2, Ne, O3

How can a element be separated?

Elements cannot be separated into simpler substances (only one type of individual atom) by chemical or physical means, as they consist of only one type of atom and are the simpler substance.

What is a simpler substance

A substance that cannot be broken down into simpler components by chemical means. And is often composed of a single type of atom, such as elements.

What is a compound

A compound is a substance made up two or more different elements chemically bonded together to make a new substance. eg H2O, NaCl

How can a compound be seperated?

A compound can only be separated by chemical mean and not physical ones.

How can pure substances be seperated?

Elements cannot be separated, while compounds can be broken down into simpler substances. Compounds can only be separated through chemical means not physical.

How to identify if substances is pure substance or mixture?

If it can be separated by a physical process i.e filtration, it’s a mixture, if not it’s a pure substance.

How to identify if mixture is homogenous or heterogenous?

If it is totally uniform (looks the same) then it’s homogenous, if not it’s heterogenous.

How to identify if pure substances is an element or compound?

If it can be broken down by a chemical process it’s a compound. If not it’s an element.