BTEC APPLIED SCIENCE
UNIT 1 CHEMISTRY WITH
CORRECT ANSWERS
How many electrons can an s subshell hold? - ANSWER --2
How many electrons can a p subshell hold? - ANSWER --6
How many electrons can a d subshell hold? - ANSWER --10
Which subshells are available in the first energy level? - ANSWER --s
Which subshells are available in the second energy level? - ANSWER --s and p
Which subshells are available in the third energy level? - ANSWER --s, p and d
What is Hund's rule? - ANSWER --Orbitals must all be singly filled before they can be
doubly occupied
Which elements do not fill the 4s subshell before the 3d subshell? - ANSWER --Copper
and chromium
,Define the term ionic bond - ANSWER --The electrostatic attraction between oppositely
charged ions
What is the charge of an ion from group 1? - ANSWER --+1
What is the charge of an ion from group 2? - ANSWER --+2
What is the charge of an ion from group 6? - ANSWER ---2
What is the charge of an ion from group 7? - ANSWER ---1
Explain how atoms of sodium react with atoms of chlorine - ANSWER --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? - ANSWER --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 - ANSWER --Size of ion and
charge on ion
When can ionic substances conduct electricity? - ANSWER --When molten or in aqueous
solution
, Describe the properties of ionic compounds - ANSWER --Conduct electricity when molten
or aqueous solution
High melting/boiling points
Usually soluble in water
Define the term covalent bond - ANSWER --A shared pair of electrons
Which metals lose electrons from the 4s subshell before the 3d subshell? - ANSWER --
Transition metals
Why do metals have such high melting points? - ANSWER --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 - ANSWER --Size of ion
Charge on ion
Explain how the charge on metal ions affects the strength of the metallic bond -
ANSWER --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 -
ANSWER --The smaller the +ve ion the closer the nucleus is to the delocalised electrons
creating a greater attraction
Explain why metals conduct electricity - ANSWER --The delocalised electrons 'carry'
charge. Current flows because of this.
UNIT 1 CHEMISTRY WITH
CORRECT ANSWERS
How many electrons can an s subshell hold? - ANSWER --2
How many electrons can a p subshell hold? - ANSWER --6
How many electrons can a d subshell hold? - ANSWER --10
Which subshells are available in the first energy level? - ANSWER --s
Which subshells are available in the second energy level? - ANSWER --s and p
Which subshells are available in the third energy level? - ANSWER --s, p and d
What is Hund's rule? - ANSWER --Orbitals must all be singly filled before they can be
doubly occupied
Which elements do not fill the 4s subshell before the 3d subshell? - ANSWER --Copper
and chromium
,Define the term ionic bond - ANSWER --The electrostatic attraction between oppositely
charged ions
What is the charge of an ion from group 1? - ANSWER --+1
What is the charge of an ion from group 2? - ANSWER --+2
What is the charge of an ion from group 6? - ANSWER ---2
What is the charge of an ion from group 7? - ANSWER ---1
Explain how atoms of sodium react with atoms of chlorine - ANSWER --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? - ANSWER --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 - ANSWER --Size of ion and
charge on ion
When can ionic substances conduct electricity? - ANSWER --When molten or in aqueous
solution
, Describe the properties of ionic compounds - ANSWER --Conduct electricity when molten
or aqueous solution
High melting/boiling points
Usually soluble in water
Define the term covalent bond - ANSWER --A shared pair of electrons
Which metals lose electrons from the 4s subshell before the 3d subshell? - ANSWER --
Transition metals
Why do metals have such high melting points? - ANSWER --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 - ANSWER --Size of ion
Charge on ion
Explain how the charge on metal ions affects the strength of the metallic bond -
ANSWER --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 -
ANSWER --The smaller the +ve ion the closer the nucleus is to the delocalised electrons
creating a greater attraction
Explain why metals conduct electricity - ANSWER --The delocalised electrons 'carry'
charge. Current flows because of this.
