This may help you
Use an arbitrary mass, 100 g is an easy number to work with.
60% of 100 g is 60 g, there are two A's. Each A is 30 g
40 g is B, and there is only one, so B is 40 g.
<span>A<span>B2</span></span>, would have a mass of 30 g + 2*40 g = 110 g
The new percent by mass composition of A is: <span><span><span>30g</span><span>110g</span></span>∗100%=27.3%</span>
The new percent by mass composition of B is: <span><span><span><span>80g</span><span>110g</span></span>∗100%=72.7%</span></span>
Hello,
I think the answer is B) It is second longest river in south america
Hope this helps!!
~Girlygir101~
B. A solar cycle usually lasts 11 years.
Answer:
The specific heat of the metal is 0.466 
Explanation:
Calorimetry is the measurement and calculation of the amounts of heat exchanged by a body or a system.
The equation that allows calculating heat exchanges is:
Q = c * m * ΔT
where Q is the heat exchanged by a body of mass m, made up of a specific heat substance c and where ΔT is the temperature variation.
In this case:
- Q= 2330 J
- c= ?
- m= 25 g
- ΔT= 200 °C
Replacing:
2330 J= c*25 g* 200 °C
Solving:

c=0.466 
<u><em>The specific heat of the metal is 0.466 </em></u>
<u><em></em></u>
1. 2 H2 + O2 = 2 H2O
2. 6 K + B2O3 = 3 K2O + 2 B
3. 10 Na + 2 NaNO3 = 6 Na2O + N2