Answer:
See Explanation
Explanation:
The question is incomplete; as the mixtures are not given.
However, I'll give a general explanation on how to go about it and I'll also give an example.
The percentage of a component in a mixture is calculated as:
Where
E = Amount of element/component
T = Amount of all elements/components
Take for instance:
In 
The amount of all elements is: (i.e formula mass of )
The amount of calcium is: (i.e formula mass of calcium)
So, the percentage component of calcium is:
The amount of hydrogen is:
So, the percentage component of hydrogen is:
Similarly, for oxygen:
The amount of oxygen is:
So, the percentage component of oxygen is:
Hey there!
I can't be sure my answers are the exact words, but it should be something along the lines of...
The amount of water on Earth is constant, but the form and location of the water changes as it moves through the water cycle.
This means that Earth has always had the same amount of water within in, along with it being the same water the whole time. No new water was introduced to our planet. Some of our water is liquid, some is solid, and some is gas. Some is deep in the soil and some is high up in the atmosphere. Some is in rain and some is in snow.
I hope this helps!
Conduction - by touch
Convection - hot air rises, cold air sinks
Insulation - to insulate or capture heat
Radiation - by waves
Direct contact means touch, therefore the answer would be conduction.
Answer:
a) a0 was 46.2 grams
b) It will take 259 years
c) The fossil is 1845 years old
Explanation:
<em>An unknown radioactive substance has a half-life of 3.20hours . If 46.2g of the substance is currently present, what mass A0 was present 8.00 hours ago?</em>
A = A0 * (1/2)^(t/h)
⇒ with A = the final amount = 46.2 grams
⇒ A0 = the original amount
⇒ t = time = 8 hours
⇒ h = half-life time = 3.2 hours
46.2 = Ao*(1/2)^(8/3.2)
Ao = 261.35 grams
<em>Americium-241 is used in some smoke detectors. It is an alpha emitter with a half-life of 432 years. How long will it take in years for 34.0% of an Am-241 sample to decay?</em>
t = (ln(0.66))-0.693) * 432 = 259 years
It will take 259 years
<em>A fossil was analyzed and determined to have a carbon-14 level that is 80% that of living organisms. The half-life of C-14 is 5730 years. How old is the fossil?</em>
<em />
t = (ln(0.80))-0.693) * 5730 = 1845
The fossil is 1845 years old
A i dolnt reaally know but yeh
