The Atom
Name the three particles found in an atom and each of their charges.
Neutron (0)
Proton (+)
Electron (-)
Elements in group 0 are also known as ..............................
noble gases
sharing
What is the chemical formula of chlorine?
Cl2
Is this equation balanced?
C2H5 + 2O2 --> 2CO2 + 2H2O
No
3 x 1023
What is the relative molecular mass of carbon dioxide?
44
Name the lightest atom.
Hydrogen, H
Elements that have the same number of electron shells are found in the same ....................... of the Periodic Table.
period
A calcium atom will form lose two electrons forming an ion of charge -2.
True/False
False
A calcium atom loses two electrons forming an ion of charge +2
What is the chemical formula of ammonia?
NH3
NH4Cl + NaOH -> NaCl + NH3 + H2O
None!
This is a balanced chemical equation :)
What is the mass of one mole of carbon-12?
12 g
The relative atomic mass is the mass of one atom relative to ...............................................
1/12 th of the mass of a carbon-12 atom
How many neutrons does an atom of sodium contain?
12
Elements in this group form cations of charge +2.
Graphite, graphene and diamond are .................... of the element .....................
allotropes, carbon
What is the chemical formula of barium nitrate?
Ba(NO3)2
What are the values of X and Y in order to balance the following equation:
X HCl + Y Ca --> CaCl2 + H2
X = 2
Y = 1
160 g
What is the relative molecular mass of ammonium sulfate?
132
Carbon-12, carbon-13 and carbon-14 are ....................... of carbon.
The difference between them is ..................................................................
isotopes
they have different number of neutrons in their nuclei-
carbon-12 has 6 neutrons, carbon-13 has 7 neutrons and carbon-14 has 8 neutrons
These metals have variable valencies and often form coloured compounds. They are found in the middle of the Periodic Table.
What type of metals are these?
Give one example of this type of metals
Transition metals
Copper, iron, manganese, chromium
Water is a covalent compound with a ................................. structure.
It has low melting and boiling points because ......................................................
simple molecular
the weak intermolecular forces of attraction can be overcome with little energy required.
What is the chemical formula of ammonium carbonate?
State one physical property of ammonium carbonate.
(NH4)2CO3
It has a high melting/boiling point
It is soluble in water
It conducts electricity in molten, gaseous and aqueous state.
Form an balanced chemical equation for the reaction.
N2 + 3H2 -> 2NH3
What is the mass of 0.1 mol of sodium nitrate?
8.5 g
Find the Mr of compound X.
74
Element X bonds with oxygen to form the compound XO. Element X has 4 electron shells.
Name element X.
calcium
Which of these elements have the same number of electron shells as silicon?
(A) argon
(B) carbon
(C) magnesium
(A) argon
(C) magnesium
Which of these compounds are soluble in water and have high melting and boiling points?
(A) iron (II) sulfate
(B) calcium
(C) graphite
(D) ammonia
(A) iron (II) sulfate
State the chemical formulae of these acids:
sulfuric acid
nitric acid
hydrochloric acid
H2SO4
HNO3
HCl
Nitric acid and iron (II) oxide react to form iron (II) nitrate and water.
Write a balanaced chemical equation for the reaction.
2 HNO3 + FeO -> Fe(NO3)2 + H2O
How many moles are present in 190 g of MgCl2?
2 mol
How many moles are present in 300 g of iron (III) hydroxide?
2.80 mol
Name and give the chemical formulae of three2 elements that exist as diatomic molecules.
hydrogen H2
oxygen O2
nitrogen N2
fluorine F2
chlorine Cl2
bromine Br2
iodine I2
An isotope is a an individual atom of an element that has more/fewer neutrons, hence is an atom that of an element with a different mass.
An allotrope is a different way in which the atoms are arranged in an element. The atoms are the same but they are just arranged differently, leading to different physical and chemical properties.
Describe the structure of particles in a metal.
Metals are made of a lattice of positive ions in a "sea" of mobile electrons.
Give the chemical formulae of silver sulfate and sulfur dioxide.
State one difference their physical properties.
Ag2SO4
SO2
1. Melting/boiling point:
Ag2SO4 has high m.p/b.p but SO2 has low m.p/b.p.
2. Electrical conductivity
Ag2SO4 conducts electricity in aqueous and molten states but SO2 does not conduct electricity.
Propane, C3H8, reacts with oxygen to form carbon dioxide and water.
Write a balanced chemical equation for this reaction.
C3H8 + 5O2 -> 3CO2 + 4H2O
Calculate the number of moles of potassium nitrate in 25 g.
0.248 mol
How many moles of sodium chloride are present in 235 cm3 of 0.6 mol/dm3 of sodium chloride solution?
0.141 mol