The true statement about the balanced equations for nuclear and chemical changes is; both are balanced according to the total mass before and after the change.
A basic law in science is called the law of conservation of mass. Its general statement is that mass can neither be created nor destroyed.
Both in chemical and nuclear changes, mass is involved and in both cases, the law of conservation of mass strictly applies.
This means that for both chemical and nuclear changes; total mass before reaction must be equal to total mass after reaction.
Hence, both reactions are balanced according to the total mass before and after the change.
Learn more: brainly.com/question/22064431
Answer : The time required for decay is, 84 days.
Explanation :
Half-life of chromium-51 = 28 days
First we have to calculate the rate constant, we use the formula :
Now we have to calculate the time required for decay.
Expression for rate law for first order kinetics is given by:
where,
k = rate constant
t = time taken by sample = ?
a = let initial activity of the sample = 100
a - x = amount left after decay process = 12.5
Now put all the given values in above equation, we get
Therefore, the time required for decay is, 84 days.
Answer: Most of them lie in a belt between Earth and Mars.
Explanation:
Asteroids are small rocky bodies having irregular shape size which orbit sun. Majority of the asteroids are found in a belt between orbits of Mars and Jupiter. Scientists presume that these asteroids are remains of a planet that never formed between Mars and Jupiter due to great gravitational pull of the largest planet of the solar -system - Jupiter.
Thus, the incorrect description of the asteroids is: Most of them lie in a belt between Earth and Mars.
