Sodium , bromine zinc magnesium sulphur nitrogen potassium oxygen lead
Answer:
b. 54.9%
Explanation:
An emerald gemstone has the formula Be₃Al₂Si₁₆O₁₈. We can find the mass of each element in 1 mole of Be₃Al₂Si₁₆O₁₈ by multiplying the molar mass of the element by its atomicity.
Be: 3 × 9.01 g = 27.03 g
Al: 2 × 26.98 g = 53.96 g
Si: 16 × 28.09 g = 449.4 g
O: 18 × 16.00 g = 288.0 g
Total mass = 818.4 g
The mass percentage of silicon is:
(449.4 g / 818.4 g) × 100% = 54.91%
Answer:
100 j
Explanation:
bascially u j subtract 50 from 150 because the system lost 50 j but theres 150 in its surroundings
Avogadro's law states that in every mole of a substance, there are 
molecules.
This means that in 2.3 moles, there are 
