Answer:
Mass = 3.24 g
Explanation:
Given data:
Number of atoms of cobalt = 3.31 × 10²² atoms
Mass of cobalt = ?
Solution:
We will calculate the number of moles of cobalt first.
1 mole contain 6.022× 10²³ atoms
3.31 × 10²² atoms × 1 mol / 6.022× 10²³ atoms
0.0549 mol
Mass of cobalt:
Mass = number of moles × molar mass
Mass = 0.0549 mol × 58.93 g/mol
Mass = 3.24 g
NaHCO3 is the required substance often used in antacid and is used in Soda Acid Fire Extinguisher.
Answer:
Explanation:
These are present in group two and have two valance electrons.
All have high melting and boiling point.
All alkaline earth metals form salt with halogens.e.g
Mg + Cl₂ → MgCl₂
Ba + Br₂ → BaBr₂
Mg + Br₂ → MgBr₂
Ca + Br₂ → CaBr₂
They react with oxygen and form oxides of respective metal.
2Mg + O₂ → 2MgO
2Ba + O₂ → 2BaO
2Ca + O₂ → 2CaO
these oxides form hydroxide when react with water,
MgO + H₂O → Mg(OH)₂
BaO + H₂O → Ba(OH)₂
CaO + H₂O → Ca(OH)₂
With nitrogen it produced nitride,
3Mg + N₂ → Mg₃N₂
3Ba + N₂ → Ba₃N₂
3Ca + N₂ → Ca₃N₂
With acid like HCl,
Mg + 2HCl → MgCl₂ + H₂
Ba + 2HCl → BaCl₂ + H₂
Ca + 2HCl → CaCl₂ + H₂
The following statement about soil formation are true:
1. The composition of soil depend largely on the composition of the parent rock.
2. Strong roots of shrubs and trees hold on to soil and protect it from erosion.
3. Soil formed from local rock is residual soil and soil formed from distant rock is transported soil.
Soil are typically formed from rocks. The nature of the soil depend on the type of rock from which the soil was formed. It takes a long time for a soil to be formed from a parent rock. Erosion is the process that carries the surface soil away, but the root of shrub and trees usually prevent this by holding on to the soil particles.