Answer:
2 HBr (aq) + CaCO3 (s) → CaBr2 (aq) + CO2 (g) + H2O (l)
Answer: Marcia made a more concentrated salt solution.
Explanation:
Marcia used 1 kg of salt, which the exercise tells us is 2.2 lb.
She dissolved it in 3L of water, so we have to find out how much that is in pints. We do that using cross multiplication.
If 1L equals 2.11 pints, then
xpints / 3L = 2.11pints / 1L, so
xpints = (3L . 2.11pints) / 1L = 6.33 pints
Now we know she dissolved 2.2lb in 6.33 pints of water. We use cross multiplication again to find out how much salt she would have in 10 pints, so we can know how concentrated it is compared to Bobby's solution, which is 10 pints.
xlb / 10pints = 2.2lb / 6.33pints
xlb = (10pints . 2.2lb) / 6.33pints = 3.47lb
So Marcia has a concentration of 3.47lb per 10 pints, whereas Bobby only has 3lb per 10 pints.
Atomic mass = 39
number of neutrons = 20
Number of protons= 19
Electronic configuration = 1s2 2s2 2p6 3s2 3p6 4s1
The number of electron in first shell = 2
number of electrons in n=3 shell = 8
Answer:
48889 years
Explanation:
Activity of the living sample Ao= 15.2 disintegration per minute
Activity of the cloth A= 8.4 disintegration per minute
Half life of 14C= 5715 years
Time taken for the decay t= the unknown
From;
0.693/5715 = 2.303/t log (15.2/8.4)
1.213 × 10^-4 = 2.303/t log (1.8095)
1.213 × 10^-4 = 0.593/t
t= 0.593/1.213 × 10^-4
t= 4888.7 years
t= 48889 years
