Kelvin = celsius + 273 so...
0 = C +273
-273 = C
some people use 273 or 273.15 just depends on the teacher.
The answer is 0.62g.
Solution:
From year 1960 to year 2030, it has been
2030-1960 = 70 years
The half-life of the radioactive element is 28 years, then the sample will go through
70 years * (1 half-life/28 years) = 2.5 half-lives
Starting with a 3.5 gram sample, we will have
3.5*(1/2) after one half-life passes
3.5*(1/2) * (1/2) = 3.5*(1/4) after two half-lives pass
3.5*(1/4) * (1/2) = 3.5*(1/8) after three half-lives pass and so on
Therefore, we can write the remaining amount of the sample after the number n of half-lives have passed as
mass of sample = initial mass of sample/2^n
The mass of the remaining sample for n = 2.5half-lives can be now calculated as
mass of sample = 3.5 grams / 2^2.5 = 0.62 g
Answer:

Explanation:
Density is found by dividing the mass by the volume.

The mass of the object is 11 grams and the volume is 13 milliliters.

Substitute the values into the formula.

Divide.

Round to the nearest hundredth. The 6 in the thousandth place tells us to round the 4 to a 5.

The density is about <u>0.85 grams per milliliter.</u>
Answer:
10 neutrons
This isotope of fluorine has 9 protons, 9 electrons and 10 neutrons.
Explanation: