Answer: 10.99
Explanation: because you take the Cao 13.9 and take CO2 which is 10.99 and it makes 24.8 . Which is CaCO3.
I'm pretty sure it's B)constructive
Answer:
Metal
Element: Calcium
Valency: 2
Explanation:
To find the element, let's use the periodic table. (Look below)
We already went past 3 shells, just need the 2 electrons after it.
Just skip to the 4th row and count 2 to the right
We end up at Calcium.
Calcium is a metal and we're also on the alkaline earth metals column.
Calcium will need to lose 2 electrons to reach stability, so the valency is 2.
Essentially all the available nitrogen for life in the form of nitrates and ammonia would eventually disappear. Nitrogen is needed to make proteins and other chemicals so it is required for all life to exist. It gets recycled so it would take many decades in most places before the available nitrogen ran out. Many crops like beans depend on it. Humans can manufacture it but it would be hard on the ecosystems of the world and eventually probably lead to the extinction of all the ecosystems of the world.
Hope this helps!
Answer:
b, H2O(s) r H2O(g)
Explanation:
entropy is heat, so increase in heat would mean water gets evaporated or melted, or both in this case. so the only choice above that showed increase in heat is from solid(ice) to gas(water vaper) due to increase in heat in the reaction.
