Which of the following liquids would have the highest viscosity at 25degc
a) ch3och3, b) ch3cl2, c) c2h5oh, d) ch3br e) hoch2ch2oh

Ethylene glycol

HOCH₂CH₂OH

Explanation:

For the molecules in the question, the viscosity will rise with the number of hydrogen bonds that can be formed.

A hydrogen bond is a week physical bond which is formed when hydrogen is found between atoms with high electronegativity (oxygen, nitrogen, fluorine):

O-H ··· O, N-H ··· O, N-H ··· O, O-H ··· N, F-H ··· F and so on.

Here we have have two compounds that can form hydrogen bonds (between themselves):

C) ethanol and D) ethylene glycol

Ethylene glycol have more hydroxide groups (-OH) than the ethanol so it will form more hydrogen bonds thus increasing its viscosity.

A Beryllium (Be) atom has 2 electron shells, whereas a Barium (Ba) atom has 6 electron shells

Explanation:

Beryllium (Be) is an element in group two of the periodic table with atomic number 4 (Is2 2s2). On the other hand, barium (Ba) is an element in group 2 of the periodic table with atomic number 56. However, as stated in the question, the Beryllium (Be) atom is smaller than the Barium (Ba) atom.

This is because a Beryllium (Be) atom has 2 electron shells, whereas a Barium (Ba) atom has 6 electron shells. The electron shells of Barium contains more electrons, which is responsible for the large size of the Barium atom. Note that, the higher the number of atoms, the larger the atomic size.