chapter 2 Atoms, ions and compounds

Fill in the table?

What is the charge of an atom and why is that?

• The charge of the proton and electron cancel each other

• This means the atom has a neutral charge (0)

Look at the positioning of the element:

• Mention the labels?

• What the label consists of?

• Relative atomic mass: weight average mass of all isotopes together

• Atomic number: ( no.of.protons)

Definition of an isotope?

Atoms of the same element with different number of neutrons and different masses but same number of protons.

What is a positive ion called?

Cation

What is a negative ion called?

Anion

Find the number of protons, neutrons, electrons for Mg²⁺ ?

Protons: 12

Neutrons: 12

Electrons: 10

What element is used and why when figuring measurements of other atomic masses?

Carbon-12 is a reference mass which you compare other atoms to it to get their relative atomic mass

Not definition but what does Relative Isotopic Mass refer to?

Relative isotopic Mass looks at one isotope

Not definition but what does Relative Atomic Mass refer to?

Looks at all the isotopes of an element added together - gives weighted average

Define Relative atomic Mass?

Weighted mean mass of an atom relative to 1/12 th of the mass of an atom of Carbon-12.

• This means the average isotopes added together

• The element atomic mass is shown on the periodic table!

Define Relative Isotopic mass?

It’s the mass of an atom of an isotope compared with 1/12th of the mass of a carbon-12 atom

• Looking at one particular type of atom!!

• Comparing it to the carbon-12 standard

What does the Relative atomic mass include?

• The percentage abundance of each isotope (%)

• The relative isotopic mass of each isotope

What experiment helps you in finding elements of relative atomic Mass?

Mass spectrum

The steps in Mass spectrometry?

1. A sample is placed in the mass spectrometer

2. The sample is vaporised and then ionised to form postive ions.

3. The ions are accelerated: - Heavier ions move slowly ( more difficult to detect than lighter ions) - Ions of each isotope are seperated!

4. Ions are detected on a mass spectrum as M/Z ratio ( mass-to-charge ratio)

Label the axis of the graph and mention the equation?

• Y axis : Percentage abundance (%)

• X axis : M/Z ( relative mass of ion / relative charge of an ion) = relative isotopic mass

isotope question:

• 75% of Chlorine- 35

• 24.22% of Chlorine- 37

( 75.78 X 35) + ( 24.22 X 37) / 100. = 35.5

Charge for NH₄?

NH₄⁺

Charge for OH?

OH^-

Charge for Nitrate?

NO₃^-

Nitrate?

NO₃

Nitrite?

NO₂

Charge for Nitrite?

NO₂^-

Charge for hydrocarbonate?

HCO₃^-

Charge for Maganate VII?

MnO₄^-

Charge for Sulfate?

SO₄^2-

Charge for Sulfite?

SO₃^2-

Charge for phosphate?

PO₄^2-

Metal + H₂O——→

Metal + H₂O——→ Metal Hydroxide (CaOH₂ ) + H₂

Metal + O₂ ——→

Metal + O₂———→ Metal oxide

Metal + Acid——-?

Salt + Water

Metal Oxide + Acid———>

Salt + water

Metal hydroxide + H₂O———>

Salt + water

Metal Carbonate + Acid ———>

Salt + water + CO₂

Metal hydrogencarbonate + Acid ———>

Salt + water + CO₂

Acid + Ammonia———→

Ammonium salt