The amount of sample that is left after a certain period of time, given the half-life, h, can be calculated through the equation.
A(t) = A(o) (1/2)^(t/d)
where t is the certain period of time. Substituting the known values,
A(t) = (20 mg)(1/2)^(85.80/14.30)
Solving,
A(t) = 0.3125 mg
Hence, the answer is 0.3125 mg.
Alpha particles are relatively heave and can be stopped by a sheet of paper.
Answer:
The plates can be thought of like pieces of a cracked shell that rest on the hot, molten rock of Earth’s mantle and fit snugly against one another. The heat from radioactive processes within the planet’s interior causes the plates to move, sometimes toward and sometimes away from each other.
Gain 1.
This is because of Chlorine's placement on the periodic table. Chlorine is a Halogen, thus being located in group 17 or 7A. This means it is one of the closest elements to being a Noble Gas or group 18/8A.
Chlorine has 7 valence electrons, and in order for it to become a Noble Gas, it needs 8. Cl- is typically the symbol used to represent this as Chlorine needs to gain an electrons instead of lose; once Chlorine gains the electron, it will be stable.
This also means that Chlorine has a high ionization energy or, in simpler terms, it would be difficult to remove an electron from Chlorine.
Hope this helps!
Physical chemistry is the area that deals with the
mechanisms, the rate, and the energy transfer that occurs when matter undergoes
a change. So the correct option for the given question is option “B”. Whenever
there is a change in the state of matter, the physical properties definitely
undergo a change. A solid matter will always have a definite shape and volume,
while a liquid has a definite volume but no shape. Gases do not have either definite
volume or shape. Chemical properties might not be affected, but physical
properties are definitely impacted when a matter undergoes change.
