Answer:
18.018 seconds.
Explanation:
Given that the half life of Manganese, Mn = 3 seconds. The initial sample mass = 90.0 gram, the final sample mass = 1.40 gram.
The general idea to the question is to look for the time it will take to decay from the initial mass that is 90 gram to 1.40 gram.
Therefore, we will be making use of the formula below;
J(t) = J(o) × (1/2)^t/t(hL).
Where t(hL) is the half life, t is the time taken, J(t)= mass after time,t and J(o) is the initial mass. So, let us slot in the values into the equation above.
1.4 = 90 × (1/2)^ t/3.
1.4/90 = (1/2)^t/3.
t/3 = log(0.5) (1.4/90).
+Please note that the 0.5 of the log is at the subscript).
That is the base 0.5 logarithm of (1.4/90) 0.01556 is 6.0060141295.
t = 3 × 6.0060141295.
t = 18.018 seconds.
Water and dimond are the 2 pure substances
A group goes vertically and a period goes horizontally.
(a group goes down and a period goes across)
The two most abundant elements in the universe are HYDROGEN AND HELIUM. Hydrogen is the most abundant element followed by helium.
Hydrogen is the lightest of all element and the first element to be formed, followed by helium which has just two atoms.
The law of conservation of mass states that mass is neither created nor destroyed. Since we have 2 g/mol of A and 3 g/mol of B then AB should be equal to the sum of their molar mass that is
2 g/mol + 3 g/mol = 5 g/mol AB
for the case of A2B3
A2 = 2 * 2 = 4 g/mol
B3 = 3 * 3 = 9 g/mol
therefore A2B3 = 13 g/mol
