Break down the table into smaller sections. Memories period by period or if you like by group (like halogens or noble gases).
Just say the elements in order everyday 1-10 then when you get those 11-20 and continued.
The solution is an alkali.
Usually with the pH value range of 14, substances with pH 7 can be called neutral. Meanwhile substances lower than pH 7 are acids, the lower the pH is, the more acidic it is. Such as cola, it has a pH 2, which is very acidic.
In opposite, the substances with pH over 7 are called alkalis. Again, the larger the pH value is, the more alkaline it is. So pH 13 is a strong alkaline therefore it it corrosive and can clean the toilet well.
Answer:
Q = 3440Kj
Explanation:
Given data:
Mass of gold = 2kg
Latent heat of vaporization = 1720 Kj/Kg
Energy required to vaporize 2kg gold = ?
Solution:
Equation
Q= mLvap
It is given that heat required to vaporize the one kilogram gold is 1720 Kj thus, for 2 kg
by putting values,
Q= 2kg × 1720 Kj/Kg
Q = 3440Kj
Equation for half-lives:
Nt = No x (1/2)^n
No = initial amount
Nt = final amount after t years
n = number of half lives = t/(single half-life)
t = years
Nt = 3/12 = 0.25
No = 12/12 = 1.00
n = t/(24400)
3/12 = (12/12) x (0.5)^(t/24400)
(0.25) = 1.00 x (0.5)^(t/24400)
0.25/1.00 = 0.5^(t/24400)
ln(0.25) = ln(0.5^(t/24400))
ln(0.25) = (t/24400)*ln(0.5)
ln(0.25)/ln(0.5) = (t/24400)
2 = t/24400
2*24400 = t
t = 48800 yrs
answer is <u>t = 48,800 yrs</u>
