Stars on the main sequence fuse hydrogen into helium via a six-stage sequence of reactions
Answer:
D. 0.160
Explanation:
The solution A is obtained adding 2.0mL of a solution of bromocresol green, 5.0mL of 1.60M HAc and 2.0mL of a solution of KCl. The solution is diluted to 50mL
That means the HAc is diluted from 5.0mL to 50.0mL, that is:
50.0mL / 5.0mL = 10 times.
And the final concentration of HAc must be:
1.60M / 10 times =
0.160M
Right answer is:
<h3>D. 0.160</h3>
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:
(B) 2AgCl + sunlight → Cl2 + 2Ag (decomposition reaction) is correct option.
Answer:
O, S, Te
Cl, Br, Se
Explanation:
Main group elements have an electronegativity that increases across a period (from left to right) and decreases down a group.
Each atom has its own value which you can find on the electronegativity chart.
Metals have low values
Nonmetals have high values
I'm your case:
O = 3.5
S = 2.5
Te = 2.1
Cl = 3.0
Br = 2.8
Se = 2.4
