Answer: This means to find the number of neutrons you subtract the number of protons from the mass number.
Answer:

Explanation:
The formula to convert Fahrenheit to Celsius, use the following formula.

We want to convert 98.7 degrees Fahrenheit to Celsius, so we must substitute 98.7 in for degrees Fahrenheit.

Solve inside the parentheses. Subtract 32 from 98.7.

Multiply 66.7 by 5/9.

98.7 degrees Fahrenheit is equal to 37.0555556 degrees Celsius
Answer:
Amplitude is measured from the center line to the highest point in the waves.
Wavelength is the distance between one wave to the other from the highest point.
Frequency is the rate of the waves.
Answer:
0.693kg of CuFeS2 is needed to produce 240 grams of Cu.
Explanation:
In 1 mole of CuFeS2 is associated 1 mole of Cu.
Molar mass of CuFeS2 = 183.5 g/mol
Molar mass of Cu = 63.5g/mol
No of moles of copper present in 240g of chalcopyrite = 240/63.5 = 3.779moles
we know
1 mole of Cu → 1 mole of CuFeS2
in 3.779 moles of Cu → 3.779 moles of CuFeS2
3.779 moles of CuFeS2 = 3.779 * 183.5 = 693.45grams
CuFeS2 in kg = 0.693kg
Answer:- 23.0 mg
Solution:- Radioactive decay obeys first order kinetics and the first order kinetics equation is:

where,
is the initial amount of radioactive substance and N is it's amount after time t. k is the decay constant.
From given information, Original amount,
of the radioactive substance is 184 mg and we are asked to calculate the amount N after 15 days. It means, t = 15 days
Half life is given as 5 days. From the half life, we could calculate the decay constant k using the equation:

where,
is the symbol for half life. let's plug in the value of half like to calculate k:


Let's plug in the values in the first order kinetics equation and solve it for N:


lnN = 3.136

N = 23.0 mg
So, 23.0 mg of Bi-210 would be remaining after 15 days.