3.1-3.7: Atoms, Elements and Compounds

Alloys

________ are mixtures of metals, where the metals are mixed together but are not chemically combined.

pure substance

A(n) ________ made up of two or more elements chemically combined.

Hydrogen

________ has 1 proton, helium has 2 protons, lithium has 3, etc.

Metallic bonding

________ is not disrupted as the outer electrons do not belong to any particular metal atom so the delocalised electrons will move with them.

Mixtures

________ can be separated by physical methods such as filtration or evaporation.

Electrons

________ orbit the nucleus in shells (or energy levels) and each shell has a different amount of energy associated with it.

Noble gases

________= All of the ________ are unreactive as they have full outer shells and are thus very stable.

powder

Eg: sand and water, oil and water, sulphur ________ and iron filings 😁.

Metals

________ have high melting and boiling points.

physical properties

The difference in mass affects the ________, such as density, boiling point and melting point.

Elements

________ are made of tiny particles of matter called atoms.

different shapes

They can be hammered and bent into ________ or drawn into wires without breaking.

Radioactive

________ have a lot of use in the medical field.

Atoms

________ are the smallest particles of matter, that we can not break down further by chemical means.

chlorine atom

Group: The final notation, which is 7 in the example, shows that a(n) ________ has 7 outer electrons.

Group VII

Chlorine is a(n) ________ non- metal so will need to gain an electron to have a full outer shell of electrons.

Radioactive isotopes

________ (radioisotopes) are unstable due to the imbalance of neutrons and protons, which causes the nucleus to decay over time through nuclear fission and emit radiation.

positive sodium ion

A(n) ________ with the charge 1+ is formed.

Ionic compounds

________ are formed when metal atoms react with non- metal atoms.

Non radioactive isotopes

________ are stable atoms which really only.

atomic number

The ________ and mass number for every element is on the Periodic Table.

Lattice structures

________: In ________, the atoms are arranged in an orderedand repeating fashion.

strong electrostatic forces of attraction

The oppositely charged ions are held together by ________.

Ionic bonds

________ happen between metals and non metals.

Isotopes

________ are atoms of the same element that contain the same number of protonsand electrons but a different number of neutrons.

Sodium

________ is a Group I metal so will lose one outer electron to another atom to gain a full outer shell of electrons.

Metallic bonds

________ are thus not broken and as a result metals are strong but flexible.

Alloys

________ contain atoms of different sizes, which distorts the regular arrangements of atoms.

how to find neutrons number

The nucleon number minus the proton number gives you the number of neutrons of an atom

example

Copper sulfate and calcium carbonate 👍🏼

Eg

sand and water, oil and water, sulphur powder and iron filings 😁

We can represent the structure of the atom in two ways

using diagrams called electron shell diagrams or by writing out a special notation called the electronicstructure

Period

 The red numbers at the bottom show the number of notations which is 3, showing that a chlorine atom has 3 shells of electrons

Group

 The final notation, which is 7 in the example, shows that a chlorine atom has 7 outer electrons

The table is arranged in vertical columns called Groupsnumbered I

VIII and in rows called Periods

Metals

 all metals can lose electrons to other atoms to become positively charged ions

Non-metals

 all non-metals can gain electrons from other atoms to become negatively charged ions

Formula of ionic compound

   NaCl

Lattice structures

In lattice structures, the atoms are arranged in an orderedand repeating fashion