Answer:
The atomic weight of an element represents the ratio of the average mass of atoms of a chemical element.
Answer:
C. They don't react with other elements to form compounds
Explanation:
The elements in Group 18 of the periodic table are called "inert", or noble gases.
These elements have their valence shell (the outermost shell of the atom) full of electrons, so they do not gain/give off electrons, and therefore, they do not react with other elements, so they do not form compounds.
In fact, normally the elements try to gain/give off electrons in order to fullfill their outermost shell (the valence shell). For instance, an atom that has 1 electron only in its valence shell, try to "give away" this electron in order to have its outermost shell completed. On the other hand, an atom which has 7 electrons in its valence shell tries to "gain" one electron in order to fullfill the valence shell.
Noble gases, instead, have already 8 electrons in their valence shell, so their valence shell is already completed, therefore they do not react with other elements, and therefore they are called "inert".
As we know that one mole of any Ideal gas at standard temperature and pressure occupies exactly 22.4 dm³ volume.
Solution for problem:
When 1 mole Neon (Ne) occupies 22.4 dm³ at STP then the volume occupied by 2.25 moles of Neon is calculated as,
= ( 22.4 dm³ × 2.25 moles ) ÷ 1 mole
= 50.4 dm³ 1dm³ = 1 L
Result:
So, 50.4 dm³ (Liter) volume will be occupied by 2.25 moles of Neon gas if it acts ideally at STP.
Answer:
CaCO3----------CaO+CO2
(40g+12g+16g×3) of CaCO3 produce (40g+16g) of CaO
100g of CaCO3 -----------------56g of CaO
20g of CaCO3-------------------x grams of CaO
x=(20g×56g)÷100g
x=1120gg÷100g
x=11.2g of CaO
Therefore, 11.2grams of CaO from 20grams of CaCO3
HOPE IT HELPED, PLEASE MARK BRAINLIEST
