Chemistry-P1 Atoms and bonding

What is an atom

The smallest part of an element that can exist

What is an element

A substance made of only one type of atom

What is a compound

A substance made of two or more different types of atoms chemically combined in fixed proportions

What is a mixture

Two or more substances mixed together but not chemically combined

What is the charge of a proton

+1

What is the mass of a proton

1

What is the charge of a neutron

0

What is the mass of a neutron

1

What is the charge of an electron

-1

What is the mass of an electron

Very small or negligible

What is the atomic number

The number of protons in the nucleus of an atom

What is the mass number

The total number of protons and neutrons in the nucleus of an atom

How do you calculate the number of neutrons

Mass number minus atomic number

What is an isotope

Atoms of the same element with the same number of protons but a different number of neutrons

What is relative atomic mass (Ar)

The average mass of the isotopes of an element compared to 1/12th of the mass of an atom of carbon-12

What is the maximum number of electrons in the first shell

2

What is the maximum number of electrons in the second shell

8

What is the maximum number of electrons in the third shell

8

What is electronic configuration

The arrangement of electrons in shells around the nucleus

Who proposed the plum pudding model

J.J. Thomson

Who discovered the nucleus using the alpha particle scattering experiment

Ernest Rutherford

Who suggested electrons orbit the nucleus at specific distances in energy levels

Niels Bohr

Who discovered the neutron

James Chadwick

How are elements arranged in the modern periodic table

In order of atomic number

What are columns in the periodic table called

Groups

What are rows in the periodic table called

Periods

Why do elements in the same group have similar chemical properties

Because they have the same number of outer shell electrons

Where are metals found on the periodic table

On the left and towards the bottom

Where are non-metals found on the periodic table

On the right and towards the top

What are Group 1 elements called

The alkali metals

What are Group 7 elements called

The halogens

What are Group 0 elements called

The noble gases

Why are noble gases unreactive

Because they have a full outer shell of electrons

What is ionic bonding

The electrostatic attraction between oppositely charged ions, formed by the transfer of electrons between a metal and a non-metal

What is a positive ion (cation)

An atom that has lost one or more electrons, resulting in more protons than electrons

What is the structure of an ionic compound

A giant ionic lattice with strong electrostatic forces of attraction acting in all directions between oppositely charged ions

Why do ionic compounds have high melting and boiling points

Because a lot of energy is required to break the strong electrostatic forces between the ions

Do ionic compounds conduct electricity when solid

No, because the ions are fixed in position and cannot move

Do ionic compounds conduct electricity when molten or dissolved in water

Yes, because the ions are free to move and carry charge

What is covalent bonding

A chemical bond formed when two non-metal atoms share pairs of electrons

What is a simple molecular substance

A substance made of small molecules with weak intermolecular forces between the molecules, resulting in low melting and boiling points

Do simple molecular substances conduct electricity

No, because they do not have an overall electric charge or free electrons

What is a giant covalent structure

A giant three-dimensional lattice of atoms bonded together by strong covalent bonds, such as diamond and silicon dioxide

What are the properties of diamond

Very hard with a high melting point, and does not conduct electricity because every carbon atom is bonded to four others with no free electrons

What are the properties of graphite

Soft and slippery with a high melting point, and conducts electricity because each carbon atom is bonded to three others, leaving one delocalized electron per atom

What is graphene

A single layer of graphite, one atom thick, which is extremely strong, lightweight, and conducts electricity

What are fullerenes

Molecules of carbon atoms with hollow shapes, such as buckyballs and carbon nanotubes

What is metallic bonding

The electrostatic attraction between positively charged metal ions and delocalized electrons

Why are metals good conductors of electricity and heat

Because the delocalized electrons are free to move through the structure and carry thermal energy and electrical charge

Why are pure metals malleable

Because the atoms are arranged in regular layers that can slide over each other easily when a force is applied

What is an alloy

A mixture of a metal with one or more other elements, usually metals or carbon

Why are alloys harder than pure metals

Because the different sized atoms distort the regular layers, preventing them from sliding over each other easily

What are the three states of matter

Solid, liquid, and gas

What is nanoscience

The science of structures that are 1 to 100 nanometres in size

What is the surface area to volume ratio of nanoparticles

Very high, which makes them extremely reactive and useful as catalysts or in medicin