1. Why is it possible to use the periodic table to predict that the first ionization energy of Mg is greater than the first ionization energy of K? Why is it not possible to use the periodic table to predict whether the first ionization energy of K or Sr is larger? [Predict = decide without looking at numerical values] 2. How does the Bohr theory of the atom explain the fact that the spectrum obtained from a glowing tube of hydrogen gas displays discrete lines and not a continuous rainbow of colors?

3. Why do we find CF4 as a stable molecule and not CF3 or CF5?

4. Is the C2ClF molecule polar or non-polar? Describe in detail how you arrived at your conclusion.

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.

answerapplication program;