Answer:36
Explanation:
Atoms must have equal numbers of protons and electrons. In our example, an atom of krypton must contain 36 electrons since it contains 36 protons. Electrons are arranged around atoms in a special way.
Answer:
94 moles of Carbon
Explanation:
From the question,
Using Avogadro's constant
1 mole of every element contains 6.03×10²³ atoms of the element
If 1 mole of Carbon contains 6.03×10²³ atoms of Carbon,
Then, x mole of Carbon will contain 5.67×10²⁵ atoms of Carbon
1 mole of C ⇒ 6.03×10²³ atoms of C
x mole of C ⇒ 5.67×10²⁵ atoms of C
solve for x
x = (1× 5.67×10²⁵)/6.03×10²³
x = 94.03 moles of Carbon
x ≈ 94 moles of Carbon
Answer:
After 9.0 hours
Explanation:
Using the decay equation, we can write the amount of drug propanol after time t as:
(1)
where
m(t) is the mass left at time t
is the initial mass of the substance
is the decay constant
t is the time
The decay constant is related to the half-life of the substance as follows:
where 
is the half-life.
Here we have
So the decay constant is
We want to find the time t after which the dose is 80% of the initial dose is eliminated, so the time t after which 20% of drug is left, so
Substituting eq(1) and solving for t, we find:
