Explanation:
The given data is as follows.
Mass of a lead atom = 
Volume = 2.00 
Density = 11.3 
As it is mentioned that 1 cubic centimeter contains 11.3 grams of lead.
So, in 2 cubic centimeter there will be 
of lead atoms.
One lead atom has a mass of . Therefore, number of atoms present in 22.6 g of lead will be as follows.
= 
Thus, we can conclude that there are of lead are present.
The answer 1) Oxygen. And another smallest radius is fluorine, because it is the first in the periodic table.
Explanation:
gravity if it's incorrect sorry
Kepler did not study the speed of the planets, rather, he studied how the planets move in the solar system. He proposed three laws. As a summary, he described that the planets move around the sun in the shape of an ellipse (orbit), and the Sun being one of the foci. Then, he proposed the period for the planet to complete one revolution around the Sun.
On the other hand, Newton studied the forces acting on the planet (or any object in space) that explain how the planets move around the solar system as described by Kepler. Also, Kepler's observations only apply to planets and not the moons or satellites. Thus, Kepler only made laws from observations, while Newton based it from underlying principles that led him to mathematical equations such as the law of universal gravitation.
