Which of the following elements has the largest atomic radius? potassium calcium cobalt nickel

            Potassium has the largest atomic radius.

                        Using periodic table trends one can easily compare the atomic radii of elements. The trends in atomic radii are as follow,

Trends in Groups:

                             Moving from top to bottom along the groups the atomic radii increases because as you move from top to bottom the number of shells increases hence, the distance of valence electrons from nucleus also increases and therefore, atomic radius increases.

Trends is Periods:

                             Moving from left to right along the periods the atomic radii decreases. This is because the number of protons and electrons increases but the the valence shell remain the same hence, causing more nuclear charge and more attraction between the valence electrons and nucleus.

           Potassium, Calcium, Cobalt and Nickle all are present in same period. Potassium present at the extreme left will have greater atomic radii of 0.227 nm while Co and Ni at the middle of period will have atomic radii of 0.125 nm each. While, the atomic radius of Calcium next to K is 0.197 nm.

top answer is correct thx

Explanation:

I took the test and potassium was the answer

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.