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.
Proton number = the atomic number (which is the smaller number
neutron number = the mass number (the bigger number) - the atomic number
number of electrons = the atomic number - the charge (it depends on the element but group 1 is +1 group 2 is +2 group 3 is +3 group five is -3 group six is -2 group seven is -1
i would solve the whole thing but its unclear hope this helps tho
I believe the answer is a because 2 times 12 is 24. Hope this helped
Answer:
1. Phosphoric Acid
: Catalyst
2. Methyl Anthranilate
: Reactive
3. Sodium Nitrite
: Reactive
4. Diethyl Ether
: Solvent and reactant
5. Nitrogen
: Sub-product
Explanation:
The phosphoric acid is used as a catalyst for the reaction, the methyl anthranilate will react with the sodium nitrite to produce methyl salicylate, along with the diethyl ether and the nitrogen is a sub-product of the reaction.
Answer:
solids
Explanation:
through solids because the molecules are closer together