Answer:
13 minutes
Explanation:
For the endothermic reaction to reach 0°C, it will take 13 minutes.
Let us follow the process step by step;
Rate of decrease is 2°C per minute.
Start is 26°C
Time temperature
0 min 26°C
1 min 24°C
2 min 22°C
3 min 20°C
4 min 18°C
5 min 16°C
6 min 14°C
7 min 12°C
8 min 10°C
9 min 8°C
10 min 6°C
11 min 4°C
12 min 2°C
13 min 0°C
Equation a. C3H8(g) + O2(g) → CO2(g) + H2O(g) + 2220 kj
is endothermic. + 2220 kj
Equation b. 2 Na(s) + Cl2(g) → 2 NaCl(s) + 819kJ
is also endothermic since the overall energy change is positive. + 819kJ
The equation c. PCl5(g) + 67kj → PCl3(g) + Cl2(g) is endothermic since it requires anergy to proceed.
Also, remember, light energy (from the sun) is a reactant for photosynthesis. The plant uses water sunlight and carbon dioxide to make sugars as well as oxygen. Plants, the organisms that carry out photosynthesis, are typically the first ate organism is a Food chain and so most other organisms energy came from the plant somehow. But the plant got its energy from the sun.
61mol * 4 = 244moles of P
1s2 2s2 2p6 3s2 3p6 3d10 4s2 4p1
Primero realizas la configuración electrónica que es la que te puse allá arriba.
Después miras el nivel en que termina, puede ser 1, 2, 3, 4 etc.
Entonces como el último número de la configuración electrónica es 4, entonces ese es el nivel
Y los electrones de el último nivel son los de Valencia
4s2, 4p1 sumas 2+1 que son los electrones que se encuentran en el último nivel.
por eso hay 3 electrones de valencia.
