There are two hydrogen and two oxygen molecules because the number next to the atomic number is how many there are.
Answer:
Because only a few bacterias can "fix" the atmosphere nitrogen.
Explanation:
The nitrogen at the atmosphere is in the form of N₂ and represents 78% of the atmosphere composition. The element is part of the constitution of nucleic acids and proteins, so the living beings needed them.
However, the animals and the plants can't catch the N₂. Some bacterias that live in mutualism with plants have this ability, and they "fix" the atmosphere nitrogen, transforming the N₂ in the ions nitrite (NO₃⁻) or ammonia (NH₃), which can be caught by the plants.
Them, when the primary consumers eat the plants they catch the nitrogen, which will be passed through the food chain.
So, it's difficult to pull nitrogen from the atmosphere into the nitrogen cycle of the biosphere because only a few bacterias can do it.
Answer:
[ Ga ] = 1.163 E-8 Kg/m³
Explanation:
- %wt = [(mass Ga)/(mass Si)]*100 = 5.0 E-7 %
⇒ 5.0 E-9 = m Ga/m Si
assuming: m Si = 100 g = 0.1 Kg
⇒ m Ga = (5.0 E-9)*(0.1 Kg) = 5 E-10 Kg
∴ density (δ) Si = 2.33 Kg/m³
⇒ Volume Si = (0.1 Kg)*(m³/2.33 Kg) = 0.043 m³
⇒ [ Ga ] = (5 E-10 Kg)/(0.043 m³) = 1.163 E-8 Kg/m³
⇒ [ Ga ] =
