He used a magnet to find that the negatively charged particles to be smaller then the atom.
He discovered electrons.
Since there are 63.01284 grams to one mole of HNO3, then 12.5 moles would be in 450 grams of it.
Lower fertility and longer lifespans steadily increased the potential labor force relative to the total population
Answer:
Explanation:
What we need to do here is to determine the ratios by using the Rydberg equation starting with the transition to n1 = 1, 2,3, etc and see which one fits the data. Remember the question states that they are series and the wavelengths will be for increasing energy levels.
1/λ = Rh x ( 1/n₁² - 1/n₂²)
Lyman series ( n₁=1 and n₂= 2,3 etc) for the first two lines, the ratios will be:
1/λ₁ /1/λ₂ =(1/1 -1/ 2²) / (1/1 -1/ 3²) ⇒ 0.84 ≠ 0.74 (the first ratio)
For Balmer series n₁ = 2 and n₂ = 3,4,5, etc
1/λ₁ /1/λ₂ =(1/4 -1/3²) / (1/4 -1/4²) ⇒ 0.741 = 0.741 (match!)
Lets use the third line to check our answer:
1/λ₁ /1/λ₂ =(1/4 -1/3²) / (1/4 -1/5²) = 0.66
Answer:
0.88g
Explanation:
The reaction equation:
2NaI + Cl₂ → 2NaCl + I₂
Given parameters:
Mass of Sodium iodide = 2.29g
Unknown:
Mass of NaCl = ?
Solution:
To solve this problem, we work from the known to the unknown.
First find the number of NaI from the mass given;
Number of moles = 
Molar mass of NaI = 23 + 126.9 = 149.9g/mol
Now insert the parameters and solve;
Number of moles = 
= 0.015mol
So;
From the balanced reaction equation;
2 moles of NaI produced 2 moles of NaCl
0.015mole of NaI will produce 0.015mole of NaCl
Therefore;
Mass = number of moles x molar mass
Molar mass of NaCl = 23 + 35.5 = 58.5g/mol
Now;
Mass of NaCl = 0.015 x 58.5 = 0.88g
