I got b 5)A sample of pure sodium-24 has an initial mass of 10.0 grams. How many grams of sodium-24 will remain at the end of 4 half-lives?
A. 0.315
B. 0.630
C. 5.00
D. 6.00
Answer:
Carbon dioxide is a compound
Explanation:
It is formed by chemical combination of carbon and oxygen atoms
The balanced chemical reaction for this would be written as:
2Mg + O2 = 2MgO
We use this reaction and the amount of the reactant given to calculate for the amount of magnesium oxide that is produced. We do as follows:
1.5 g Mg (1 mol / 24.31 g) ( 2 mol MgO / 2 mol Mg ) (40.30 g /1 mol ) = 2.49 g MgO produced
Answer:
8.2 x 106^-11
Explanation:
To begin this problem you must remember the basic rule of scientific notation, which is, must be between 1-10. .000000000082 is much smaller than 1. However by moving the decimal 11 spots to the right, we can make it 8.2
Continue to move the decimal to the right until the value is in the 1-10 range. Make sure to count the moves to the right.
Once the decimal is in the right spot count the spots moved.
Since the number is wayyy smaller than the answer given the number will be negative 10^-11, in order to make it what is was before.
