What are ions?

A charged atom or molecule. number electrons dont equal the number of protons

When group 1 metals react with oxygen, what do they form?

Metal oxides. (group 1s are metals)

in Group 1, do the boiling points increase or decrease as you move down the collum?

The boiling points increase. This is because there are more electronic and it is harder to overcome the intermolecular forces

To show ionic bonding what type of diagrams do we use?

Dot and cross diagrams

What are covalent bonds?

When non metals share pairs of electrons

What is a double covalent bond?

when two atoms share two pairs of electrons

How many covalent bonds are there in diamond?

there are 4 covalent bonds. Diamond has a very rigid structure

how many covalent bonds are there in graphite?

There are 3 covalent bonds. Creates layers of hexagons. Layers slide over eachother easily as they are weakly held together. Each carbon atom has a delocalised electron.

What does a delocalised electron mean?

A free electron

What is graphene?

Graphene is one layer of graphite

Why are alloys stronger than pure metals?

an alloy is a mixture of metals with another element. the different sized atoms of the pure metal and other element are different sizes making it more difficult to slide making them stronger.

what is the range of the PH scale?

0-14

The higher the PH of a solution...

the more alkaline it is.

what does a neutral substance have a Ph of?

7

Ph scale goes from ______ -> _____ ->____

Acidic -> neutral -> alkali

How do you measure Ph electrically?

By placing a pH probe in a solution which is attached to a pH meter

what is an acid?

a substance with a pH lower than 7

What is a base?

A substance with a pH higher than 7

Do weak acids fully ionise in water?

No. they don't fully ionise in water and the reaction can be reversed.

What is the reactivity series?

Metals are listed In order or reactivity.

What is silicon dioxide?

silicon and oxygen in a covalent bond. Solicon dioxide is a giant covalent structure (sand)

What structure do ionic compounds have?

A giant ionic lattice. it has strong electrostatic forces of attraction between opposite charged ions in all directions.

What is the name given to group 0 elements?

Noble gases. they have 8 elections in outer shell. Domt react as stable and are colourless and non flammable

what is meant by a displacement reaction?

One element is displaced because another element is more reactive.

what is the name given to the elements in group 7?

halogens. highly reactive. they are non metal. as you go down the group they become less reactive.

What does group 1 metals when reacted with water produce?

Hydrogen gases

What do period's represent on a periodic table?

Each period is another full shell of electrons.

What do the groups tell us on a periodic table?

How many electrons the element has in its outer shell. Each group is likely to react in a similiar way.

What is rock salt?

Rock salt is a mixture of salt and sand. used on the roads in winter. Salt for melting the ice and sand for grip.

What are the 5 physical separation techniques?

Simple distillation, fractional distillation, Filtration, paper chromatography and crystalisation

What is ionic bonding?

compounds formed with metals and non metals

What are isotopes?

an element with the same number of protons but a different number of neutrons.

What is an element?

A substance made up of atoms with the same number of protons in their nucleus.

What is metallic bonding?

Atoms held together in a regular structure by forces of attraction

why does metallic bonding involve delocalised electrons?

the electrons in the outer shell of the metal atoms are free to move. the metallic bond is the force of attraction between these delocalised electrons and ions

What are fullerenes?

Molecules of carbon shaped like hollow balls. they are used to cage other molecules (eg drug)

What are the 3 main examples of giant covalent structures?

diamond, graphite and silicon

what are giant covalent structures?

Bonded by strong covalent bonds. they have high melting points and don't conduct electricity.

What are polymers?

Long chains of repeating units made up of covalent bonds

What is empirical formula?

The amount of atoms in each element.

What are the properties of ionic compounds?

High melting and boiling points . can't conduct electricity unless it is melted.

what are ions?

Charged particle

When halogens react with non metals to form compounds what is the molecular structure like?

it is a simple molecular structure. made up of covalent bonds.

What do group 1 metals produce when reacting with chlorine?

A salt.

What do alkali metals only react to form?

Ionic compounds

What are group 1 elements know as?

Alkali metals. reactive low boiling points. very reactive.

What happens to the reactions even you go down group 1?

The reactions become more vigorous

Describe simple distillation

separating liquids from a solution

What is crude oil?

Extracted from the ground. A mixture of different lengths of hydrocarbon molecules.

What is relative atomic mass?

The average mass by taking into account the different masses and amounts.

How is a state changed to another state?

By either beating and breaking the bonds or cooling and doesn't have enough energy to overcome the forces

What is a compounds atomic mass?

All the masses of the elements in the compound added together.

What is a mole?

6.02 ×10 ²³ = 1 mole

what is 1 mole of an element equal to?

the relative formula mass of that substance

How many moles are there in 66g of CO2?

c = 12 O = 16 12 + 16 + 16 =44 66÷4==1.5mols

What mass of carbon is there in 4 moles of CO2?

number of moles (4) x mass of carbon (12) = 48g

What does it mean by mass is conserved?

No atoms are destroyed or created. In a chemical reaction mass is always conserved.

What is the only reason a gas in a chemical reaction would change?

mass lost through evaporation or gas floating around goes inside the container of chemical reaction

What are limiting reactants?

When one reactant is used up and the reaction stops

mass that's given of an element=

number of moles × mass of the element

how do you measure the ph of a solution?

By using an Indicator. the universal indicator shows the colours on a pH scale.

What is an indicator?

a dye that changes colour due to ph

What are wide range indicators?

a mixture of dyes that gradually changes colour over a broad range of ph

why do acids form H+ ions?

Because it reacts with water molecules by giving a proton to them

What do alkalis form in water?

OH - ions

what is the reaction called between acids and bases?

neutralisation

Acid + base ->

salt +water

what do strong acids do in water?

Fully ionise and release h+ ions

Acid + metal oxide ->

salt + water

Acid + _____ ______ -> salt + water

metal hydroxide

Acid + metal carbonate -->

salt + water + carbon dioxide

Acid +metal ->

salt + hydrogen

what do the rate of hydrogen bubbles show?

speed of reaction

metal + water ->

metal hydroxide + hydrogen

what is a reduction reaction?

a reaction that seperates a metal from its oxide

what is meant by oxidation?

gain of oxygen and loss of electons(oilrig)

what is meant by reduction?

loss of oxygen and gain of electrons(oilrig)

what is oil rig?

oxidation is loss, reduction is gain (electrons)

some metals can be extracted by reduction by using what?

Carbon

How are metals below carbon in the reactivity series extracted ?

Reduction by using carbon

Metals higher than carbon in the reactivity series are extracted by using what?

Electrolysis

what is electrolysis?

splitting up with electricity

What is an electrolyte?

liquid solution that can conduct electricity

what is an electrode?

A solid that can conduct electricity. it is submerged in an electrolyte.

in electrolysis, positive ions go towards the...

cathode (negative electode) gain electrons (reduced)

in electrolysis, negative ions move towards the...

anode (positive electrode) loose electrons (oxidised)

How do you measure the amount of energy released by a chemical reaction?

Take the temperature of reactant, mix the solution in a polystyrene cup (insulation)and then place a lid (stop evaporation) then message the mixed solution (chemical reaction)

what is a endothermic reaction?

When heat is absorbed (taken in) an example of this is sports injury packs. shown by fall in temperature around object.

what is an exothermic reaction?

heat given out. shown by a rise in temperature around object.

what type of process is bond breaking?

endothermic

what type of process is exothermic?

Bond forming

what is a redox reaction?

A reaction when electrons are transferred

what is only shown in an ionic equation ?

the particles that react and products they form

what is concentration?

How much acid there is in a certain volume

how do you work out the concentration?

mass of the solute ÷ volume if the solvent

how do you work out the percentage mass of an element in a compound

atomic mass × number of atoms of that element ÷ mass of compound then x 100

in exothermic reactions the energy released by forming the bonds is....

..greater than the energy used to break the bonds

in endothermic reactions the energy used to break the bonds is...

...greater than the energy released by forming the bonds