Answer:
It is just slightly less abundant than its alkali cousin, sodium. Potassium is less dense than water, so it can float on water. However, chemically, potassium reacts with water violently. It will give off hydrogen and eventually catch fire.
Answer:
"Urban area is used for the buildings, industries etc, whereas the rural areas are used for cultivation, forest cover etc."
Explanation:
When we talk about the urban land they are mostly covered with buildings, industries, roads and apartments and also the municipal structures. But when we talk about the rural land it has less dense population with forest cover, agricultural lands, rangeland and also different land cover type. In the urban areas the population density is very high. Those areas that located in the outskirt of the town are the rural areas.
Answer: A molecule of hydrochloric acid, for example, is composed of a hydrogen atom and a chlorine atom. When these molecules dissolve into water, they separate into a positively charged hydrogen ion and a negatively charged chlorine ion. ... Only some of the molecules of weak acids disassociate when added to water.
Explanation:
Answer:
c. -1020.9 kJ
Explanation:
4Fe (s) + 3 O₂ (g) --> 2 Fe₂O₃(s) ΔH = -826.0 kJ/mol.
atomic weight of iron = 56
69.03 g = 69.03 / 56
= 1.23268 moles
Heat released by 1.23268 moles
= 1.23268 x 826.0
= -1020.9 kJ .
Answer:
2,14 g / ml
Explanation:
Sabemos que el volumen de una sustancia es igual al cambio de volumen del agua cuando el objeto en cuestión se sumerge en el agua.
Dado que el volumen original del agua = 50 ml
Volumen de agua después de sumergir el objeto = 120 ml
Masa del objeto = 150 g
Ahora,
Densidad = masa / volumen
Densidad = 150g / 120-50 ml
Densidad = 150/70 ml
Densidad = 2,14 g / ml
