BTEC Applied Science All - Questions/Answers
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
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
