To calculate the number of atoms of Cr, we first find the number of moles per unit of cubic centimeter of Cr. Then, use avogadros number for the number of atoms. Calculations are as follows:
1 cm^3 (7.15 g/cm^3) (1 mol / 51.996 g Cr) = 0.14 mol Cr
0.14 mol Cr ( 6.022 x 10^23 atoms Cr / 1 mol Cr ) = 8.28 x 10^22 atoms Cr
Answer:
1.022ppm is the unknown concentration of the metal
Explanation:
Based on Lambert-Beer law, the increasing in signal of a detector is directly proportional to its concentration.
The unknown concentration (X) produces a signal of 0.255
99mL * X + 1mL * 100ppm / 100mL produces a signal of 0.502
0.99X + 1ppm produce 0.502, thus, X is:
0.255 * (0.99X + 1 / 0.502) =
X = 0.503X + 0.508
0.497X = 0.508
X =
1.022ppm is the unknown concentration of the metal
Answer:
156.4g K
Explanation:
I'm not sure if it is correct but I think it should be this
What do we know so far?: 2K + 1Cl2 -> 2KCl, 2 mol of Cl2
What are we looking for?: #g of K
What is the ratio of K to Cl2?: 2:1
Set up equation: 2molCl2 x 
Cancel unwanted units: 2 x 
Answer we got: 2 x 2mol K = 4mol K
Converting moles to grams: 4 x 39.1 (molar mass of K) = 156.4g K
Answer:
C. 1 proton 3 neutrons
Explanation:
A nucleus is more stable if the ratio of the neutrons to protons is between 1:1 and 1:1.5.
Thus the ratios of neutrons to protons for the nuclei are as follows
A- 1:1
B- 1:1
C- 1:3
D- 1:2
Among these ratios, C is the greatest thus the nucleus is the least stable.
