Answer:
The correct answer is - hard water reacts to form the calcium or magnesium salt of the organic acid of the soap.
Explanation:
Soaps are made up of fatty acids or oils by treating with strong alkali and are salts of sodium and potassium. Hard water, on the other hand, has a high concentration of minerals in comparison to soft water. When hard water and soap are mixed together the salts of the minerals like Ca2+ and Mg2+ ions present in hard water react with fatty acids of the soap.
The sodium salts are changed to the salts of calcium and magnesium which are precipitated to an insoluble substance. The insoluble salts of the calcium or magnesium dirt stick on the clothes thus cleaning ability of soap is reduced.
Her discovery of radium and polonium.
She was the first woman to win a nobel prize and a second one as well!
Marie Curie was the first women to be appointed as the director of the physics lab at Sorbonne.
She was also the first woman to become a professor at the University of Paris.
She helped make radiology units which were again portable and those assisted the field surgeons during the war.
Hope this helps :))
Answer:
Number of boxes = 4
Explanation:
Given:
Mass of one box of jello = 250 grams
Total quantity want to purchase = 1 kg = 1 × 1,000 gram = 1,000 grams
Find:
Number of boxes in 1,000 grams = ?
Computation:
Number of boxes = Total quantity want to purchase / Mass of one box of jello
Number of boxes = 1,000 / 250
Number of boxes = 4
Therefore, 4 boxes of jello must be purchase to get 1 kg of Jello.
Answer:
The edge length of a face-centered cubic unit cell is 435.6 pm.
Explanation:
In a face-centered cubic unit cell, each of the eight corners is occupied by one atom and each of the six faces is occupied by a single atom.
Hence, the number of atoms in an FCC unit cell is:
In a face-centered cubic unit cell, to find the edge length we need to use Pythagorean Theorem:
(1)
Where:
a: is the edge length
R: is the radius of each atom = 154 pm
By solving equation (1) for "a" we have:
Therefore, the edge length of a face-centered cubic unit cell is 435.6 pm.
I hope it helps you!
