D)
Density is equal to mass/volume, so in your case:
density=1.3/1000=0.0013 g/cm^3
<u>Answer:</u>
<em>A water strider can walk along the surface of earth due to the surface tension of water.
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<u>Explanation:</u>
Fluids have a <em>tendency to shrink to minimum possible surface area</em> and this is called surface tension. It usually occurs due to the greater force of cohesion between molecules of same substance when compared to adhesive force between molecules of different substances. Objects with greater densities can float along water surface due to the <em>role played by surface tension.
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When insects walk along the water surface they are pulled down due to gravity. But the force of attraction between the legs of the insect and water molecules is minimal. Thus the surface tension would always tend to maintain the <em>flatness of water overcoming</em> the push by the legs of the strider.
When the insect’s weight pulls it down , the surface tension pushes it upwards overcoming this force of gravity. This is how<em> water striders move along the surface of water. </em>
Answer: There is an unsolved mystery surrounding Titan's atmosphere: Because methane is broken down by sunlight, scientists believe there is another source that replenishes what is lost. One potential source of methane is volcanic activity, but this has yet to be confirmed.
Explanation:
On the regular ground, water usually seeps in to the soil, which has a number of benefits for the wildlife in that area. However, with asphalt and concrete, there is no soft and absorbent soil to take in the water, so it just keeps flowing down to the lowest part of land it can. Additionally, some water runoff can carry fertilizer and other harmful chemicals with it in to the oceans and lakes it’s dumped in, which harms the ecosystem in them as well.
