Answer:
The rule is especially applicable to carbon, nitrogen, oxygen, and the halogens, but also to metals such as sodium or magnesium. ... All four of these electrons are counted in both the carbon octet and the oxygen octet, so that both atoms are considered to obey the octet rule.
a) To find the mass after t years:we will use this formula:
A = Ao / 2^n when A =the amount remaining
and Ao = the initial amount
and n = t / t(1/2)
by substitution:
∴ A = 200 mg/ 2^(t/30y)b) Mass after 90 y :by using the previous formula and substitute t by 90 y
A = 200mg/ 2^(90y/30y)
∴ A = 25 mgC) Time for 1 mg remaining:when A= Ao/ 2^(t/t(1/2)
so, by substitution:
1 mg = 200 mg / 2^(t/30y)
∴2^(t/30y) = 200 mg by solving for t
∴ t = 229 y
The cell membrane acts as a semi-permeable barrier in plants. In other words, is in charge or control of what comes in and out of the cell.
Substances that have a define size and shape and vibrating particles that are close together are called Solid.
Explanation:
There are three states of matter - solid, liquid and gas.
Lets talk about solid state in detail.
In solid particles are closely packed and so they have very less or no space to move which results in vibrating particles. This results in solid substances having a fixed shape and volume.
The particles have very little space in between them, so it is not easy to compress solid.
There is no free space for particles to slide over each other, which does not allow solids to flow.
Also, particles in solid have a regular arrangement, they are not randomly packed.
Answer:
Fossil B
Explanation:
Fossil B is older because it's later is at the bottom