Hey there!
The best way to balance chemical equations is to first start by balancing polyatomic ions such as OH and SO₄.
Next, balance other elements, but save elements that are by themselves for last, such as H₂ or Fe. Once you balance everything else you can do the ones by themselves, it's much easier.
Hope this helps!
Answer: 
atoms of hydrogen are there in
35.0 grams of hydrogen gas.
Explanation:
According to avogadro's law, 1 mole of every substance occupies 22.4 L at STP and contains avogadro's number 
of particles.
To calculate the moles, we use the equation:
1 mole of hydrogen 
= 
atoms
17.5 mole of hydrogen = 
atoms
There are atoms of hydrogen are there in
35.0 grams of hydrogen gas.
respiratory and lymphatic
Hey there!
Solid Sodium and water will react spontaneously and release energy. This is based on the reactivity series. Sodium is a highly reactive metal and hence, it is placed at the top of the reactivity series. This is because it loses its outermost electron very readily. When it comes in contact with water, it reacts with it violently to form sodium hydroxide and hydrogen gas. This reaction is exothermic and hence, accompanied with a release of energy. Gold lies at the bottom of the reactivity series as it is very stable and does not give away its outermost electrons easily. Therefore, when it comes in contact with water, there is no reaction and no release of energy.
