Atoms, Elements and Compounds Structured Questions | Cambridge O Level Chemistry

Question 1 of 9 · 10 marks

Atoms, Elements and Compounds · Covalent Bonding & Simple Molecules

4 parts

Chemistry 5070 · Question 1[10 marks]

Magnesium exists naturally as three isotopes: $\ce{^{24}Mg}$ , $\ce{^{25}Mg}$ , and $\ce{^{26}Mg}$ . The mass spectrum chart shows their relative abundances: $\ce{^{24}Mg}$ (78.9%), $\ce{^{25}Mg}$ (10.0%), and $\ce{^{26}Mg}$ (11.1%).

(a)

State the number of protons, neutrons, and electrons present in a $\ce{^{26}Mg^{2+}}$ ion.

[3]

(b)

Calculate the relative atomic mass, Ar, of Magnesium to two decimal places. Show your working clearly.

[3]

(c)

Explain why $\ce{^{24}Mg}$ and $\ce{^{26}Mg}$ have identical chemical properties.

[2]

(d)

State the electronic configuration of a $\ce{^{24}Mg}$ atom and a $\ce{^{24}Mg^{2+}}$ ion.

[2]