Every 2 million years the amount is halved
0 million = 200g
2 million = 200g/2 = 100g
4 million = 100g/2 = 50g
Answer: The equation is written below.
Explanation:
According to Stoichiometry of the reaction:
2 moles of phosphate ions reacts with 1 mole of aluminum sulfate to produce 2 moles of aluminum phosphate precipitate and 3 moles of sulfate ions.
Aluminum phosphate is an odorless and white crystalline solid
The chemical equation is written above.
Iodine has an electronegativity of 2.5, and potassium has an electronegativity of 0.8, so the difference is:
2.5 - 0.8 = 1.7
Given, half life of a certain radioactive element = 800 years.
Amount of substance remaining at time t = 12.5%
Lets consider the initial amount of the radioactive substance = 100%
Using the half life equation:
A = A₀(1/2)^t/t₁/₂
where A₀ is the amount of radioactive substance at time zero and A is the amount of radioactive substance at time t, and t₁/₂ is the half-life of the radioactive substance.
Plugging the given data into the half life equation we have,
12.5 = 100 . (1/2)^t/800
12.5/100 = (1/2)^t/800
0.125 = (0.5)^t/800
(0.5)^3 = (0.5)^t/800
3 = t/800
t = 2400 years
Thus the object is 2400 years old.
Answer: Electronegativity increases as the size of an atom decrease.
Explanation: Electronegativity is the measure of the ability of an atom in a bond to attract electrons to itself.
Electronegativity increases across a period and decreases down a group.
Towards the left of the table, valence shells are less than half full, so these atoms (metals) tend
to lose electrons and have low electronegativity. Towards the right of the table, valence shells are more than half full, so these atoms (nonmetals) tend to gain electrons and have high electronegativity.
Down a group, the number of energy levels (n) increases, and so does the distance between the nucleus and the outermost orbital. The increased distance and the increased shielding weaken the nuclear attraction, and so an atom can’t attract electrons as strongly.
