Which is the correct name of a compound that is formed by si and o? silicon dioxide silicon trioxygen disilicon dioxygen monosilicon oxide

The correct is tricky, be careful. The right is silicon dioxyde (SiO2)

Silicon Oxides are written in the form SiOx, (0 <x <2), so:

there is no silicon trioxygen and disilicon dioxygen.

SiO is called silicon monoxide and not monosiicon oxygen, so this proposition is false.

All that remains is the silicon dioxide (SiO2) that is written correctly.

Silicon dioxide can be synthesized but also exists in abundance in nature. Silicon (Si) represents about 26% of the Earth's crust. Silica (SiO2), the natural form of silicon dioxide, accounts for about 60%.

the density(ratio between mass and volume as m/v) decreases from top to bottom in periodic table group as the size increases and nuclear charge decreases. but in periods density increases from left to right as atom size decreases and nuclear charge increases.

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.