BTEC UNIT 1 APPLIED SCIENCE CHEMISTRY
EXAM 2025-2026 QUESTIONS AND ANSWERS
GRADED A+
Which elements do not fill the 4s subshell before the 3d subshell?
Copper and chromium
Define the term ionic bond
The electrostatic attraction between oppositely charged ions
Describe the properties of ionic compounds
Conduct electricity when molten or aqueous solution
High melting/boiling points
Usually soluble in water
Define the term covalent bond
A shared pair of electrons
,Which metals lose electrons from the 4s subshell before the 3d subshell?
Transition metals
Why do metals have such high melting points?
Strong force of attraction between positive ions and delocalised electrons. This
requires a large amount of energy to overcome.
What is the charge of an ion from group 1?
+1
What is the charge of an ion from group 2?
+2
What is the charge of an ion from group 6?
-2
What is the charge of an ion from group 7?
,-1
Explain how atoms of sodium react with atoms of chlorine
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
How many electrons can an s subshell hold?
2
How many electrons can a p subshell hold?
6
How many electrons can a d subshell hold?
10
Which subshells are available in the first energy level?
s
, Which subshells are available in the second energy level?
s and p
Which subshells are available in the third energy level?
s, p and d
What is Hund's rule?
Orbitals must all be singly filled before they can be doubly occupied
Why do ionic bonds have such high melting points?
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
Size of ion and charge on ion
When can ionic substances conduct electricity?
EXAM 2025-2026 QUESTIONS AND ANSWERS
GRADED A+
Which elements do not fill the 4s subshell before the 3d subshell?
Copper and chromium
Define the term ionic bond
The electrostatic attraction between oppositely charged ions
Describe the properties of ionic compounds
Conduct electricity when molten or aqueous solution
High melting/boiling points
Usually soluble in water
Define the term covalent bond
A shared pair of electrons
,Which metals lose electrons from the 4s subshell before the 3d subshell?
Transition metals
Why do metals have such high melting points?
Strong force of attraction between positive ions and delocalised electrons. This
requires a large amount of energy to overcome.
What is the charge of an ion from group 1?
+1
What is the charge of an ion from group 2?
+2
What is the charge of an ion from group 6?
-2
What is the charge of an ion from group 7?
,-1
Explain how atoms of sodium react with atoms of chlorine
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
How many electrons can an s subshell hold?
2
How many electrons can a p subshell hold?
6
How many electrons can a d subshell hold?
10
Which subshells are available in the first energy level?
s
, Which subshells are available in the second energy level?
s and p
Which subshells are available in the third energy level?
s, p and d
What is Hund's rule?
Orbitals must all be singly filled before they can be doubly occupied
Why do ionic bonds have such high melting points?
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
Size of ion and charge on ion
When can ionic substances conduct electricity?
