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%
A major concept to remember: “Nature seeks the lowest energy state”. In the lowest energy state, things are most stable...less likely to change. The following information that talks about stability is all based on the nucleus tending towards the lowest energy state. Stable atoms have low energy states.
All nu
solution:
density x volume=mass volume x volume
13.6gml x 3.55ml
thus,the object has a mass of 98.3g
means 0.5 raise to the power of n. "To the power of" means an action of multiplication of 0.5 to n times.
The different values of n are given in the table. Substituting these values:
For A:
n = 1 (given)
For B:
n = 2 (given)
For C:
n = 3 (given)
For D:
n = 6 (given)
For E:
n = 8 (given)
Hence, the values are:
A = 0.5
B = 0.25
C = 0.125
D = 0.015625
E = 0.00390625
Density of a substance is defined as the mass of the substance divided by the volume.
Density of the substance= 0.242 g cm⁻³
volume of the substance= 2.50 in³
As, 1 in³= 16.39 cm³
So, 2.50 in³= 16.39× 2.50 cm³=40.97 cm³
As ,
Mass=volume ×Density
Mass=40.97 × 0.242
Mass=9.916 g.
