Answer:
139.98 g to nearest hundredth.
Explanation:
Using Avogadro's Number:
One mole (167.26 g) of Erbium equates to 6.022141 * 10^23 atoms.
So 5.04 * 10^23 = 167.26 * 5.04/6.022141
= 139,98 g.
Answer : The molecular weight of a substance is 157.3 g/mol
Explanation :
As we are given that 7 % by weight that means 7 grams of solute present in 100 grams of solution.
Mass of solute = 7 g
Mass of solution = 100 g
Mass of solvent = 100 - 7 = 93 g
Formula used :

where,
= change in freezing point
= temperature of pure water = 
= temperature of solution = 
= freezing point constant of water = 
m = molality
Now put all the given values in this formula, we get


Therefore, the molecular weight of a substance is 157.3 g/mol
Classical physics that matter cannot be created or destroyed in an isolated <span>system</span>
Answer:
A chemical reaction happens when substances break apart or combine to form one or more new substances.
Explanation:
hope its right.
Each of the prefixes means a different thind:
Nano means 0.000000001
Kilo means 1000
Milli means 0.001
Centi means 0.01
Out of these four, the biggest is b: 1 kilogram