<h2>Answer:</h2>
<u>When a plant cell is placed in a hypo-tonic solution It becomes turgid and hard.</u>
<h2>Explanation:</h2>
A hypotonic solution refers to a solution that has less solute and more water than another solution. When the plant cell is placed in a hypotonic solution, it takes up water by osmosis and starts to swell, but the cell wall prevents it from bursting. The plant cell is said to have become "turgid" i.e. swollen and hard. The pressure inside the cell rises until this internal pressure is equal to the pressure outside.
The heaviest elements settled in the Earth's center.
The Earth on the other hand starts with a core of iron and radioactive materials such as uranium and plutonium, which release energy in the form of heat, through a process known as nuclear fission. It went through a fusion stage - a "liquid-pasty" state - which allowed that, due to gravity, the denser materials sank towards the center, while the lighter ones floated towards the crust, a process called planetary differentiation.
