Year 9 - Chemistry - 22-11-14

Thai Sikh International School

E-Learning Programme – Online Assignment –   21/11/2014

Name:                                                                                                                 Subject: Chemistry

Year   : Y 9                                                                                                Schedule No. :     5     

1. (a) The full chemical symbols of four elements are shown below.

₁H¹

₈O¹⁶

₁₂Mg²⁴

₁₈Ar⁴⁰

Use this information to answer (i) to (iv) below.

(i) Name the element which does not react with any of the others and explain your answer.

Name:

Explanation:   

                                                                                                                   

(ii) Name a pair of elements which combine together to form an ionic compound.

                                                                            and                                                

(iii) Name two elements whose atoms have electrons in three energy levels (shells).

                                                                     and                                                                  

(iv) State and explain which of the symbols above shows an atom which does not contain any neutrons.

Symbol:

Explanation:

(b) Magnesium reacts with dilute hydrochloric acid according to the equation below.

Mg + 2HClà MgCl₂ + H₂

Explain why this equation is said to be balanced.

End of Assignment