Chemistry ncea level 1

What are atoms made up of?

Protons- positive charge

Neutrons- negative charge

Electrons- have a negative charge

Where are protons and neutrons found?

The nucleus

Where are electrons found?

In the shell of the atom

How many electrons can the first shell hold?

2

How many electrons can the second she'll hold

8

What charge are atoms?

Neutral

Why are atoms neutral

Same number of positive protons as negative electrons

What is the atomic number

Position the element is on the periodic table

What is protons always the same as

The atomic number

What is the mass number

Protons + neutrons

How is neutrons found?

Mass number - atomic number

What is an ion?

An ion is an atom that had lost or gained electrons to gain and full and stable outer shell and therefore carries a charge

What are vertical columns on the periodic table called

Groups

What are horizontal rows on the periodic table called?

Periods

What do elements in the same group all have in common?

Same number of electrons

What are positive ions called?

Cations

What will positive ions (metals and hydrogen) name change to?

Keep their element name

What are negative ions called?

Anions

What do negative ions name change to?

Have the suffix -ide

What does polyatomic atoms mean?

Made up of many atoms

What do polyatomic atoms names change to?

Have the suffix -ate

What is an ionic compound?

Electrons are transferred between atoms to form positive and negative ions. Opposite charges between positive and negative ions create a strong attractions

How do acids taste?

Sour

How do bases taste?

Bitter or salty

What ions do acids contain?

Hydrogen

What ions do bases contain?

Hydroxide

What pH do acids have?

Less than 7

What pH do bases have?

pH greater than 7

What colour do acids turn universal indicator?

Red, orange or yellow

What colour do bases turn with universal indicator?

Blue or purple

What is a molecule

Found when two or more atoms are joined together chemically

What is a compound?

A molecule that cannot be separated into simpler substances

What is an ionic bond?

Bonds that are formed between two atoms usually a metal and a non metal through losing or gaining electrons

What are covalent bonds?

Bonds usually between two non - metals and are formed when atoms share electrons to get a full and stable outer shell

What is a base?

Substance that neutralises an acid

What is an alkali?

A soluble base (able to be dissolved in water)

What does the collision theory state?

In order for a chemical reaction to occur two reactants must collide with enough force and at the right orientations

Concentration

The higher the concentration the more particles there are in a given volume

Surface area

The greater the surface area the more particles there are exposed to each other so there are more collisions per second

Temperature

The higher the temperature the more kinetic energy the particles have so the faster the particles move so there are more collisions per second. More collisions have sufficient energy.

Why is rate of reaction fastest at the start of a reaction?

More particles available for collisions

Why does a reaction stop?

All reactants have reached and there are no particles left to collide