Answer:
4 g after 58.2 years
0.0156 After 291 years
Explanation:
Given data:
Half-life of strontium-90 = 29.1 years
Initially present: 16g
mass present after 58.2 years =?
Mass present after 291 years =?
Solution:
Formula:
how much mass remains =1/ 2n (original mass) ……… (1)
Where “n” is the number of half lives
to find n
For 58.2 years
n = 58.2 years /29.1 years
n= 2
or 291 years
n = 291 years /29.1 years
n= 10
Put values in equation (1)
Mass after 58.2 years
mass remains =1/ 22 (16g)
mass remains =1/ 4 (16g)
mass remains = 4g
Mass after 58.2 years
mass remains =1/ 210 (16g)
mass remains =1/ 1024 (16g)
mass remains = 0.0156g
To determine the pOH assuming water is the universal solvent take the value of 10 ^ -14 and then divide it by the hydronium concentration and then take the negative logarithm of the final answer that is the solution to the hydroxide ion concentration in the solution.
Answer: Option B
Explanation:
Dead space is the volume of sir in the body which is inhaled but it does not takes part in the gaseous exchange this is because it does not contains alveoli.
Not all the air that is inhaled inside the body is used in the process of respiration.
The dead space in the lungs is the region which helps in conducting airways, the air is not perfused to the alveoli.
Answer:
all these are physical properties except release of heat so it's probably heat energy given off
The law of conservation of mass states that mass is neither created nor destroyed. Since we have 2 g/mol of A and 3 g/mol of B then AB should be equal to the sum of their molar mass that is
2 g/mol + 3 g/mol = 5 g/mol AB
for the case of A2B3
A2 = 2 * 2 = 4 g/mol
B3 = 3 * 3 = 9 g/mol
therefore A2B3 = 13 g/mol
