BTEC All Applied Science
How many electrons can an s subshell hold? - ANS-2
How many electrons can a p subshell hold? - ANS-6
How many electrons can a d subshell hold? - ANS-10
What is Hund's rule? - ANS-Orbitals must all be singly filled before they can be doubly
occupied
Define the term ionic bond - ANS-The electrostatic attraction between oppositely
charged ions
What is the charge of an ion from group 1? - ANS-+1
What is the charge of an ion from group 2? - ANS-+2
What is the charge of an ion from group 6? - ANS--2
What is the charge of an ion from group 7? - ANS--1
Explain how atoms of sodium react with atoms of chlorine - ANS-Na loses its 2s1
electron gaining a +ve charge.
Cl gains an electron in the 3p subshell gaining a -ve charge.
The opposite charges attract to form NaCl
Why do ionic bonds have such high melting points? - ANS-Each +ve ion is surrounded
by 6 -ve ions and vice versa.
Strong electrostatic attraction in every direction.
Requires a large amount of energy to break
State two factors that affect the strength of an ionic bond - ANS-Size of ion and charge
on ion
When can ionic substances conduct electricity? - ANS-When molten or in aqueous
solution
,Describe the properties of ionic compounds - ANS-Conduct electricity when molten or
aqueous solution
High melting/boiling points
Usually soluble in water
Define the term covalent bond - ANS-A shared pair of electrons
Which metals lose electrons from the 4s subshell before the 3d subshell? -
ANS-Transition metals
Why do metals have such high melting points? - ANS-Strong force of attraction between
positive ions and delocalised electrons. This requires a large amount of energy to
overcome.
State the two factors that affect the strength of metallic bonding - ANS-Size of ion
Charge on ion
Explain how the charge on metal ions affects the strength of the metallic bond -
ANS-The larger the +ve charge the greater the attraction between the nucleus and the
delocalised electrons
Explain how the size of the metal ions affects the strength of the metallic bond -
ANS-The smaller the +ve ion the closer the nucleus is to the delocalised electrons
creating a greater attraction
Explain why metals conduct electricity - ANS-The delocalised electrons 'carry' charge.
Current flows because of this.
Explain why metals conduct heat - ANS-Particles are paced tightly so kinetic energy is
passed from ion to ion. The delocalised electrons also enable heat to be passed.
Explain why metals are ductile and malleable - ANS-The lattice structure allows layers
of metal ions to slide over each other without disrupting bonding
Name the 3 forces between molecules - ANS-Van der Waals
Permanent dipole-dipole
Hydrogen bonds
Order the 3 forces between molecules in order of strongest to weakest - ANS-Hydrogen
, bonds
Permanent dipole-dipole
Van der Waals
How are Van der Waal's forces formed? - ANS-Electrons move to one side, caused
temporary dipole. This induces a temporary dipole in neighbouring molecules. Attraction
occurs between oppositely charged dipoles
In what molecules do Van der Waal's forces exist? - ANS-Non-polar molecules
How are permanent dipole-dipole forces formed? - ANS-Permanent dipole in one
molecule attracts oppositely charged permanent dipole in neighbouring molecule
In which molecules do permanent dipole-dipole forces exist? - ANS-Polar molecules
Which elements must be present for hydrogen bonds to exist? - ANS-Hydrogen and
either nitrogen, oxygen or fluorine
What is meant by the term displacement? - ANS-When a more reactive element takes
the place of a less reactive element in a compound
State the equation for determining moles - ANS-Moles = mass ÷ relative atomic mass
(molar mass)
(Mass= mr X moles)
Define the term Avogadro's Constant - ANS-The number of atoms in a mole of a given
substance
What is the equation for calculating % yield? - ANS-% yield = (actual yield ÷ theoretical
yield) x 100
What is a group on the periodic table? - ANS-A vertical column
What is a period on the periodic table? - ANS-A horizontal row
Define the term first ionisation energy - ANS-The energy required to remove the
outermost electron from one mole of gaseous atoms to produce one mole of gaseous
+1 ions
How many electrons can an s subshell hold? - ANS-2
How many electrons can a p subshell hold? - ANS-6
How many electrons can a d subshell hold? - ANS-10
What is Hund's rule? - ANS-Orbitals must all be singly filled before they can be doubly
occupied
Define the term ionic bond - ANS-The electrostatic attraction between oppositely
charged ions
What is the charge of an ion from group 1? - ANS-+1
What is the charge of an ion from group 2? - ANS-+2
What is the charge of an ion from group 6? - ANS--2
What is the charge of an ion from group 7? - ANS--1
Explain how atoms of sodium react with atoms of chlorine - ANS-Na loses its 2s1
electron gaining a +ve charge.
Cl gains an electron in the 3p subshell gaining a -ve charge.
The opposite charges attract to form NaCl
Why do ionic bonds have such high melting points? - ANS-Each +ve ion is surrounded
by 6 -ve ions and vice versa.
Strong electrostatic attraction in every direction.
Requires a large amount of energy to break
State two factors that affect the strength of an ionic bond - ANS-Size of ion and charge
on ion
When can ionic substances conduct electricity? - ANS-When molten or in aqueous
solution
,Describe the properties of ionic compounds - ANS-Conduct electricity when molten or
aqueous solution
High melting/boiling points
Usually soluble in water
Define the term covalent bond - ANS-A shared pair of electrons
Which metals lose electrons from the 4s subshell before the 3d subshell? -
ANS-Transition metals
Why do metals have such high melting points? - ANS-Strong force of attraction between
positive ions and delocalised electrons. This requires a large amount of energy to
overcome.
State the two factors that affect the strength of metallic bonding - ANS-Size of ion
Charge on ion
Explain how the charge on metal ions affects the strength of the metallic bond -
ANS-The larger the +ve charge the greater the attraction between the nucleus and the
delocalised electrons
Explain how the size of the metal ions affects the strength of the metallic bond -
ANS-The smaller the +ve ion the closer the nucleus is to the delocalised electrons
creating a greater attraction
Explain why metals conduct electricity - ANS-The delocalised electrons 'carry' charge.
Current flows because of this.
Explain why metals conduct heat - ANS-Particles are paced tightly so kinetic energy is
passed from ion to ion. The delocalised electrons also enable heat to be passed.
Explain why metals are ductile and malleable - ANS-The lattice structure allows layers
of metal ions to slide over each other without disrupting bonding
Name the 3 forces between molecules - ANS-Van der Waals
Permanent dipole-dipole
Hydrogen bonds
Order the 3 forces between molecules in order of strongest to weakest - ANS-Hydrogen
, bonds
Permanent dipole-dipole
Van der Waals
How are Van der Waal's forces formed? - ANS-Electrons move to one side, caused
temporary dipole. This induces a temporary dipole in neighbouring molecules. Attraction
occurs between oppositely charged dipoles
In what molecules do Van der Waal's forces exist? - ANS-Non-polar molecules
How are permanent dipole-dipole forces formed? - ANS-Permanent dipole in one
molecule attracts oppositely charged permanent dipole in neighbouring molecule
In which molecules do permanent dipole-dipole forces exist? - ANS-Polar molecules
Which elements must be present for hydrogen bonds to exist? - ANS-Hydrogen and
either nitrogen, oxygen or fluorine
What is meant by the term displacement? - ANS-When a more reactive element takes
the place of a less reactive element in a compound
State the equation for determining moles - ANS-Moles = mass ÷ relative atomic mass
(molar mass)
(Mass= mr X moles)
Define the term Avogadro's Constant - ANS-The number of atoms in a mole of a given
substance
What is the equation for calculating % yield? - ANS-% yield = (actual yield ÷ theoretical
yield) x 100
What is a group on the periodic table? - ANS-A vertical column
What is a period on the periodic table? - ANS-A horizontal row
Define the term first ionisation energy - ANS-The energy required to remove the
outermost electron from one mole of gaseous atoms to produce one mole of gaseous
+1 ions
