If a “sample” of pennies contained 75 heads and 25 tails, how many half‐lives would have passed since the “sample” formed. Expla
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An element is a substance that can't be broken down further. Lithium (Li) and calcium (Ca) are examples of elements.
Carbon monoxide (CO) and potassium bromide (KBr) are examples of compounds, which are made up of more than one element put together.
The half life for C14 is 5730 years.
We assume that Carbon 14/ Carbon 12 ratio was steady for living organisms over time, the problem is actually telling us that
= 0.0725 = 
ˣ
Take the natural logarithm and In on both sides.
ln(0.725) = lnˣ
= - 0.3216 = xln ( = -0.6931x.
So x = (-.3216) / (-0.6931) = 0.464
or
t/t₁/₂ = 0.464
So t = 0.464 x t₁/₂ = 0.464 * 5730 yrs = 2660 years.
We assume that Carbon 14/ Carbon 12 ratio was steady for living organisms over time, the problem is actually telling us that
Take the natural logarithm and In on both sides.
ln(0.725) = ln
= - 0.3216 = xln (
So x = (-.3216) / (-0.6931) = 0.464
or
t/t₁/₂ = 0.464
So t = 0.464 x t₁/₂ = 0.464 * 5730 yrs = 2660 years.
Answer: Correct options are as follows.
- salt is not chemically bonded to water.
- salt and water retain their own chemical properties.
Explanation:
When salt is dissolved in water then it means that it is a physical change as salt has completely dissociated into ions but they are not chemically combined to the water molecules.
As a result, both salt and water will retain their chemical properties.
For example, NaCl when dissolved in water will dissociate as follows.
Only the particles of salt have evenly distributed in water.
And, when a components of a salt chemically combine with another substance then it will form a new compound.
Therefore, we can conclude that salt dissolved in water is a solution, therefore:
- salt is not chemically bonded to water.
- salt and water retain their own chemical properties.