This table shows the mass of one atom for five chemical elements. Use it to answer the question given.

Element	Mass of atom (kg)
Titanium	$7.95\times {10}^{-26}$
Lead	$3.44\times {10}^{-25}$
Silver	$1.79\times {10}^{-25}$
Lithium	$1.15\times {10}^{-26}$
Hydrogen	$1.674\times {10}^{-27}$

Which is the heaviest element?

 This table shows the mass of one atom for five chemical elements. Use it to answer the question given.

Which element is lighter, Silver or Titanium$?$

 This table shows the mass of one atom for five chemical elements. Use it to answer the question given.

 List all five elements in order from lightest to heaviest.$?$

The planet Uranus is approximately $2,896,819,200,000 \mathrm{metres}$ away from the Sun. What is this distance in standard form$?$

Express the figure in usual form.

The volume of the Earth is approximately $7.67\times {10}^{-7}$ times the volume of the Sun.

At the end of the ${20}^{\mathrm{th}}$ century, the world population was approximately $6.1\times {10}^9$ people. Express this population in usual form. How would you say this number in words$?$

While studying her family's history. Shikha discovers records of ancestors $12$ generations back. She wonders how many ancestors she has had in the past $12$generations. She starts to make a diagram to help her figure this out. The diagram soon becomes very complex.

 Make a table and a graph showing the number of ancestors in each of the $12$ generations.