Dec 21 Exam

Question 1

Isotopes

Answer 1

An atom of an element with the same number of protons but a different number of neutrons

Question 2

Name the forces and particles in the structures of chlorine and silicon and explain why chlorine has a much lower melting point than silicon

Answer 2

Cl2 has van der waals forces between molecules
Si has covalent bonds between atoms

Van der waals are weaker than covalent bonds

Less energy needed to break forces in chlorine

Question 3

Name the forces and particles in the structures of chlorine and silicon and explain why chlorine has a much lower melting point than silicon

Answer 3

Cl2 has van der waals forces between molecules
Si has covalent bonds between atoms

Van der waals are weaker than covalent bonds

Less energy needed to break forces in chlorine

Question 4

Explain why the melting point of magnesium is higher than that of sodium

Answer 4

Mg has more delocalised electrons

Mg ions have a greater charge

Forces between + ions and electrons

More energy needed to break stronger forces in mg

Question 5

A student bubbles chlorine gas through an aqueous solution of MgI2

Describe what the student would see

Answer 5

Turns yellow

Question 6

Define first ionisation energy

Answer 6

Energy needed to remove an electron from each atom in one mole of gaseous atoms