Answer:
Universe.
Explanation:
Biosphere is just a planet. Solar system contains planets and star. Galaxy holds multiple solar systems only. Universe hold everything, biospheres, solar systems, and galaxies. I hope this helps :D
Answer is D
Balance the equation
Answer:
Explanation:
Salt water intrusion can cause the <u><em>fresh</em></u> water in wells to become contaminated with<u><em> salt</em></u>water.
Answer:
Therefore, the rate of change in the amount of salt is 

Explanation:
Given:
Initial volume of water
lit
Flowing rate = 5 
The rate of change in the amount of salt is given by,
( Rate of salt enters tank - rate of sat leaves tank )
Since tank is initially filled with water so we write that,

Let amount of salt in the solution is
,


Therefore, the rate of change in the amount of salt is 

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%