Science Test on elements/atoms

Democritus’ Discoveries

Matter is composed of small, indivisible particles called atoms and atoms are eternal and vary in shape and size.

Dalton’s Discoveries

Each element is composed of unique atoms and chemical reactions alter the arrangement of these atoms (link between elements and atoms), made atomic theory

Lavoisier’s Discoveries

Matter cannot be created or destroyed

Newland’s Discoveries

Atoms can be arranged in 8 groups with similar properties (Law of octaves)

Mendeleev’s Discoveries

Dreamt of atoms in a pattern, periodic table (not completed)

Periodic table

a table in which elements are listed in order of their atomic number, and grouped according to their similar properties, periodic table we use today identifies the many different properties of every atom that has been discovered or created so far

Natural philosopher

did not carry out experiments, but proposed hypotheses based on thought and reasoning (opposite is scientist)

Atomic Theory

the theory that all matter is made up of atoms (Dalton made it)

Atom

the smallest particle of matter; cannot be created, destroyed or broken down

(indivisible)

Monatomic

Consisting of a single atom (for elements) (e.g. neon and helium)

Diatomic Molecule

A molecule that consists of 2 atoms (atoms in the gases [elements]) (e.g. oxygen, hydrogen and nitrogen)

Molecule

group of two or more atoms bonded together (e.g. a water molecule)

Period

(in chemistry) a horizontal list of elements in the periodic table

Group

(in chemistry) a vertical list of elements in the periodic table that have characteristics in common

Molecular Element

a molecule that contains two or more of the same atoms bonded together

Compound

a substance made up of two or more types of atoms bonded together (e.g. water)

Molecular Compound

a molecule that contains two or more different atoms bonded together

Mixture

a substance made up of two or more pure substances mixed together

Polymer

a long-chain molecule formed by the joining of many smaller repeating molecules (monomers)

Molecular substances can be broken into 2 groups, which ones?

Those with only one type of atom (molecular element, oxygen), and those with two or more types of atoms (compounds [molecular compound = carbon dioxide])

Pure Substance

something that contains only one type of substance (e.g. a single element or a single compound)

Solution

a mixture of a solute dissolved in a solvent

Suspension

a cloudy liquid containing insoluble particles

Colloid

a type of mixture that always looks cloudy because clumps of insoluble particles remain suspended throughout it rather than settling as sediment

5.1 - All matter is made up of atoms - key ideas

All matter is made up of atoms & Scientists refine models over time.

5.2 - Elements are made up of 1 type of atom - key ideas

An element is a pure substance with one type of atom. & The periodic table organises elements according to their chemical and physical properties.

5.3 - key ideas

Molecules are groups of two or more atoms that are bonded together. & When the atoms are different elements bonded together, they can also be called compounds. & Elements and compounds can be represented by chemical formulas, while mixtures cannot.

5.4 - Matter can be modelled - key ideas

Elements are represented by symbols. & Compounds and molecules are represented by formulas. & Mixtures are represented by percentages.

Representing colour - Carbon

Black

Representing colour - Hydrogen

White

Representing colour - Oxygen

Red

Representing colour - Nitrogen

Blue

Representing colour - Fluorine

Yellowish green

Representing colour - Chlorine

Light green

Representing colour - Sulfur

Yellow

Representing colour - Phosphorus

Purple