The gravitational force between the spheres is

where <em>G</em> = 6.674 x 10⁻¹¹ N m²/kg².
The weight of the lighter sphere is

where <em>g</em> = 9.80 m/s².
The ratio between the two forces is then

Answer:
5730 years
Explanation:
The half life of carbon-14 is 5730 years. If 50% of the carbon-14 remains, then exactly 1 half life has passed.
The half-life equation is:
A = A₀ (½)^(t / T)
where A is the remaining amount,
A₀ is the initial amount,
t is time,
and T is the half life.
In this case, A = ½ A₀ and T = 5730.
½ A₀ = A₀ (½)^(t / 5730)
½ = (½)^(t / 5730)
1 = t / 5730
t = 5730
<span>The outermost energy level of an element are called the valence shell, that holds the valence electrons. they consist of the highest energy level. In aluminum, the valence electrons are 3. </span>