Hydrogen bonds.
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Lithium, Sodium, Potassium; any of the Alkali Metals, which are farthest left on the periodic table. This is because they only have one electron in their outermost shell, so they would rather lose an electron rather than try to gain 7 to achieve that full outer shell.
Mass of Hydrogen gas required to react : 0.936 g
<h3>Further explanation</h3>
Reaction on Nitrogen gas and Hydrogen gas to produce Ammonia gas
N₂ (g) + 3 H₂ (g) ⇒ 2 NH₃ (g)
Conditions at T 0 ° C and P 1 atm are stated by STP (Standard Temperature and Pressure). At STP, Vm is 22.4 liters / mol
so mol Nitrogen for 3.5 L at STP :

From the equation, mol ratio of N₂ : H₂ = 1 : 3, so mol H₂ :

then mass of Hydrogen(MW= 2 g/mol) :

Answer:
a chemical change is usually an irreversible chemical reaction. an example of this is rusting.
a physical change is usually visible while a chemical change isn't. also, a chemical change is irreversible while a physical change is.
Explanation:
A cube has a volume of 8.0 cm3 and a mass of 21.6 grams. ... using an electronic analytical balance. ... graduated cylinder ... The density of iron is 7.87 g/mL.