Answer:
The correct answer is -
A. 2.6 × 10^9 years.
B. two half-lives.
Explanation:
According to the question, the half-life of potassium-40 is, 1.3 × 10^9 years, which means it takes 1.3 billion years to decay or disintegrate half of the initial amount of the potassium.
The half-life of K-40 = 1.3 × 10^9
The number of half-life, => (1/2)^2 = 1/4 (25% =1/4)
n = 2
number of half life = two
the time it takes = n*half lifetime
= 2 *1.3 × 10^9
=2.6 × 10^9 years.
I'm pretty sure the answer is D. Sedimentary Rock. Hope this helps!
The Voluntary Sector is usually comprised of organizations whose purpose is to benefit and enrich society, often without profit as a motive and with little or no government intervention.
Unlike the private sector where the generation and return of profit to its owners is emphasized, money raised or earned by an organization in the voluntary sector is usually invested back into the community or the organization itself.
The rate of cell growth is increasing,its takes about 20 hours to grow 10 ells ,but it only takes 2-3 hr to grow the last 20 cellsExtend your thinking: In living organisms, the cell cycle is closely regulated.
I'll give a few, Plants, animals, meteors or bones.
