<span>Anthracite is also referred to as hard coal because it is so hard and pure. It is very hard and highly compacted with variety of coal that has submetallic luster. It has highest carbon content, the lowest impurities, and highest density of energy of all the coal deposits.</span>
Answer:
Mass of 1 mole of copper is 63.83 g.
0.03916 moles of copper atoms have a mass equal to the 2.5 grams of copper penny.
Explanation:
Mass of 1 copper atom,m = 

Mass of 1 mole of copper :
= 
Mass of 1 mole of copper = 63.83 g
Mass of copper penny = 2.5 g
Atomic mass of copper = 63.83 g/mol
Moles of copper in 2.5 g of copper penny:

0.03916 moles of copper atoms have a mass equal to the 2.5 grams of copper penny.
Answer:
Explanation:
Chemically, we can have a reaction between chlorine gas and solid sodium
This reaction is actually explosive and would produce fine powder of sodium chloride
We have the reaction as follows:

Essentally, what we can deduce from here is that we do not need to add water to the flask. Except for the reason that we would want the sodium chloride solid in the solution form, there is absolutely no reason to add water to the flask as the reaction would proceed normally
The number of protons an element has is the same as the atomic number, so the element would have 86 protons.
Answer:
Check the image file attached
Explanation: