The element with 4 protons in the nucleus in Beryllium.
Seeing signs of a chemical reaction does not always mean that a reaction is happening. For example, a gas (water vapor) is given off when water boils. ... You can tell that it is a physical change because water vapor can condense to form liquid water. In a chemical change, a new substance must be produced.
Okay so we are given these requirements:
element which can be used to stuff
bottles that enclose ancient paper
must be a gas at room temperature
must be denser than helium
must not react with other elements
The only element that comes into my
mind is:
<span>Argon</span>
Answer:
solution given:
Explanation:
4Fe +3O2------------>2Fe2O3
4mole. 3mole. 2 mole
224g. 96g. 320g
we have
224 g of fe needed to react completely with 96 g of O2
500g of fe needed to react completely with
96 ×500/224=214.3g of O2
214.3g of O2 is a required answer.
Answer is B. gas formation