Compare the properties of elements in groups 17 and group 18. Make sure to cover the following points: a. What type of elements are found in each group?
b. Describe the reactivity of the elements in each group
c. Are the properties of both groups of elements different or similar?
d. Explain why the two groups of elements have been placed side by side.
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a) Explain why:

(i) All the elements of a group have similar chemical properties.

(ii) All the elements of a period have different chemical properties.

(b) The atomic radii of three elements X, Y and Z of a period of the periodic table are 186 pm, 104 pm and 143 pm respectively. Giving a reason arrange these elements in the increasing order of atomic number in the period.

Letter: C

explanation:

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hloride, what is the mass of calcium in

explanation: