The heat changes the physical structure into a chemical structure because some of the cells in the physical structure are removed to make that physical structure a chemical structure
Igneous rock that forms from magma that cools slowly within Earth’s crust is likely to have larger crystals and a coarse-grained texture.
Igneous rock that forms from lava that cools quickly on Earth’s surface is known as extrusive igneous rock. Another word for extrusive is volcanic.
Because the sample of igneous rock formed on Earth’s surface, it is extrusive. Because it’s composed of mostly light-colored minerals, it is likely felsic.
Because the sample of igneous rock formed within Earth’s crust, it is intrusive. Because it contains a very high concentration of dark-colored, high-density minerals, it is likely ultramafic.
The fact that gabbro is an igneous rock suggests that it was formed from the cooling and crystallization of magma. The fact that it is intrusive means that it formed within Earth’s crust. The fact that it’s mafic suggests that it contains a high concentration of dark-colored, high-density minerals.
Answer:
Examples of Chemical Changes
Burning wood.
Souring milk.
Mixing acid and base.
Digesting food.
Cooking an egg.
Heating sugar to form caramel.
Baking a cake.
Rusting of iron.
M = 22.1 g
V = 52.3 mL
D = ?
D = m/V
= 22.1/52.3
= 22.1*10/52.3*10
= 221/523
= 0.4
There. I’m sorry i forgot what exactly was the S.I. unit of density :(
The radioactive decay obeys first order kinetics
the rate law expression for radioactive decay is
![ln\frac{[A_{0}]}{[A_{t}]}=kt](https://tex.z-dn.net/?f=ln%5Cfrac%7B%5BA_%7B0%7D%5D%7D%7B%5BA_%7Bt%7D%5D%7D%3Dkt)
Where
A0 = initial concentration
At = concentration after time "t"
t = time
k = rate constant
For first order reaction the relation between rate constant and half life is:

Let us calculate k
k = 0.693 / 72 = 0.009625 years⁻¹
Given
At = 0.25 A0

time = 144 years
So after 144 years the sample contains 25% parent isotope and 75% daughter isotopes**
Simply two half lives