That statement is true
it was easy to organize 'all' the elements in a group of threes because back then they only knew about 15 - 20 elements
hope this helps
Answer: 462 g
Explanation:molar mass is M= 63.55 +2·(12.01+14.01)= 115.59 g/mol.
Mass m= n·M = 4.0 mol·115.59 g/mol= 462.36 g
The classification of it being a metal, nonmetal, or metalliod will be useful in the process of elimination to determine what it is. Then for the second test, meauring the atomin radius will narrow it down quicker to the mystery elemet's name.
Since you determined what part of the periodic table it's on, then when measuring the atomic radius, you should be able to pinpoint what the element is more surely.
Answer:
1.5055×10²⁴ molecules
Explanation:
From the question given above, the following data were obtained:
Number of mole CO₂ = 2.5 moles
Number of molecules CO₂ =?
The number of molecules present in 2.5 moles CO₂ can be obtained as:
From Avogadro's hypothesis,
1 mole of CO₂ = 6.022×10²³ molecules
Therefore,
2.5 mole of CO₂ = 2.5 × 6.022×10²³
2.5 mole of CO₂ = 1.5055×10²⁴ molecules
Thus, 1.5055×10²⁴ molecules are present in 2.5 moles CO₂