5 * 1 point
Two elements are in the same group of the Periodic Table.
Which property will be the same for both elements?
A the charge on their ions
B their electronic structure
C their melting point
D their reactivity with water or acids
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A. the charge on their ions

Explanation:

Elements are grouped into the same group in the periodic table if they have the same valence electrons. However, the number of valence electrons an element has, determines the number of charges it can possess.

According to this question, two elements in the same group of the periodic table will have the same charge on their ions because they both have the same number of valence electrons.

pure substance: iron,copper

impure substance: water,charcoal

the best answer is d because the strong cohesion is caused by the ability of water molecules to undergo hydrogen bonding.

a is incorrect because when water solidifies, it becomes   ice, which expands and occupies a bigger volume for the same mass of water in its liquid state.

b is incorrect because water has high surface tension. besides bonding to itself it hydrogen bonds to other molecules at the top decreasing possibility for breaking of attractive forces.

c is incorrect because the water molecule has oxygen which is highly electronegative and so pulls the electron pair towards itself creating a dipole moment, making the molecule polar.

e is incorrect because water has strong adhesion, ability to stick to other molecules such as glass because of this molecules having stronger hydrogen bonding than water.