Answer:
3.9 billion years
Explanation:
The half-life of potassium-40 is the time it takes for half of it to decay.
After one half-life, half of the original amount will remain.
After a second half-life, half of that amount will remain, and so on.
We can construct a table as follows:
We see that the mass will drop to 10 g after three half-lives.
1 half-life = 1.3 billion years
3 half-lives = 3.9 billion years
Answer:
Different things make different vibrations when they hit, and that's why you hear high notes and low notes. Things that vibrate quickly make small waves in the air, and that sounds to you like a high-pitched note. Things that vibrate slowly make longer waves in the air, that sound to you like a low-pitched note.
Answer:
8.18 × 10 ⁻²¹.
Explanation:
The potential energy may be defined as the energy stored in the rest objects. This energy is important for the maintenance of the concentration gradient in the cell.
The change in the potential energy can be calculated as follows:
W = v2-v1 × q.
Here, the charge of the proton is considered because k+ ions has been used.
W= 0 - ( - 70. 5 mV) × 1.602 * 10^-19 C.
W= 8.18 × 10 ⁻²¹J.
Thus, the answer is 8.18 × 10 ⁻²¹.
Calcium
Calcium helps build and maintain bones.
