Answer:
a mole have have wrong becouse i understand
Answer:
The situation given here is imaginary such that the life of Rock has to be found using the half-life of the element lokium that has been found inside the rock.
Half-life of any material is the amount of time taken by that particular material to decay. Now the amount of lokium found in rock can show after how many half-lives this amount has been left out.
The time elapsed will be log (L) atoms X half-life.
Explanation:
Given :
A 250 ml beaker weighs 13.473 g .
The same beaker plus 2.2 ml of water weighs 15.346 g.
To Find :
How much does the 2.2 ml of water, alone, weigh .
Solution :
Now, mass of water is given by :

Therefore , mass of 2.2 ml of water alone is 1.873 g .
Hence , this is the required solution .
Answer:
H =2; I = 2; J = 2
Explanation:
Carbon is element 6 in the Periodic Table.
Start at element 1 (H) and count from left to right until you reach element 6 (C).
You get the electron configuration
C: 1s² 2s²2p².
Thus,
H =2; I = 2; J = 2