NEET Practice Questions (MCQs) with Answers & Solutions

$ Pb_3O_4 $ is mixed oxide. It can be represented as $ 2PbO – PbO_2 $

Noble gas are found in very minute amount in atmosphers. These are separated from each other by using coconut char coal. Which absorb different gas at different tempera tures.

When hydrogen peroxide reacts with PbS then they forms $ PbSO_4 $

Silicon occurs in combined state in nature as silica, $ SiO_2 $

It is hydrolysed with water to form a $ Si(OH)_4 $

$\text{SiF}_4$ gets hydrolyzed by water to form silicic acid ($\text{Si(OH)}_4$). The reaction is as follows: $\text{SiF}_4 + 4\text{H}_2\text{O} \rightarrow \text{Si(OH)}_4 + 4\text{HF}$. Silicic acid further polymerizes to form a gel-like substance, which helps in understanding why $\text{SiF}_4$ hydrolyzes to silica gel.

Silicon is a major constituent of rocks and minerals. It is found in the form of silicon dioxide ($\text{SiO}_2$) or silicates. Silicon is not found in amalgams, chlorophyll, or haemoglobin. Rocks and minerals like quartz are primarily composed of silicon dioxide, making silicon an essential component of the Earth's crust.

In a carbon atom, the electronic configuration is $1s^2 2s^2 2p^2$. The 2p orbital has two unpaired electrons. Therefore, the number of unpaired electrons in a carbon atom is 2.

Metal oxides or some salts are fused with glass to imparted colour of glass.

Safety glass is specifically designed to break into small, less harmful pieces when shattered. This property makes it ideal for use in the windscreen of automobiles to reduce the risk of injury in case of an accident.