The atomic mass of Europium is 152 amu
Work:
151(0.4803) = 72.52 amu
153(0.5197) = 79.5 amu
72.5 + 79.5 = 152 amu
Answer: 13.9 g of 
will be produced from the given mass of oxygen
Explanation:
To calculate the moles :
The balanced chemical reaction is:
According to stoichiometry :
7 moles of 
produce = 6 moles of
Thus 0.900 moles of will produce =
of
Mass of 
Thus 13.9 g of will be produced from the given mass of oxygen
Alkina metals all have the similar proteries
To calculate the atomic mass of a single atom of an element, add up the mass of protons and neutrons.
Answer:
first option is not true
Explanation:
1 mole = 6.02 × 10²³ particles
C3H8 has 1 mole, so has 6.02 × 10²³ particles
5O2 has 5 moles so 5 × 6.02 × 10²³ = 3.01 × 10²⁴ particles
3CO2 has 3 moles so 3 × 6.02 × 10²³ = 1.806 × 10²⁴ particles
4H2O has 4 moles so 4 × 6.02 × 10²³ = 2.408 × 10²⁴ particles
