Answer:
The conversion of liquid water into gaseous water is a chemical change
Explanation:
A chemical change occurs when there is a chemical reaction, so there'll be changed in the compounds, such as forming new ones, forming its elements, or elements forming compounds.
A physical change occurs when there is a change in the state of aggregation of the compound, it means that it changes its physical state. Solid for liquid, liquid for solid, liquid for gas, gas for liquid, solid for gas, and gas for solid are the physical changes.
So the evaporation of water, or its conversion in gaseous water, is a physical change, not a chemical change.
The chemical equation is:
CH₄ + 2O₂ → CO₂ + 2H₂O
First, we calculate the moles of methane present using:
Moles = mass / molecular mass
Moles = 20 / 16
Moles = 1.25
Next, we may observe from the chemical equation that the molar ratio between methane and oxygen is 1 : 2
So the moles of oxygen required are 2 x 1.25
2.5 moles of oxygen required
Mass = moles * molecular mass
Mass = 2.5 * 32
Moles = 80
C. 80 grams O₂
The answer is Ra
Atomic number for Be is 4
Atomic number for Mg 12
Atomic number for Ra 88
Atomic number for Ba 56
