<h2>Answer : Option D) Heterogeneous mixture</h2><h3>Explanation : </h3>
A mixture in which particles are not evenly distributed and particles keep their unique properties are called as heterogeneous mixture.
Usually, in heterogeneous mixture the substances are not evenly distributed and they can be easily separated through any physical methods. Also the components retains their original/unique properties in the mixture. It usually contains various particles from different substances that are not uniformly distributed throughout the mixture.
Answer:
20 mol
Explanation:
First, balance the chemical reaction
C3H8 + 5O2 --> 4H2O + 3CO2
Using the mole ratio, we can multiply the moles of propane by 4 to find the moles of H2O.
5 × 4= 20
20 mol
B) oxygen, because oxygen is the only element that is in both chemical formulas.
Answer: 
Explanation:
General representation of an element is given as: 
where,
Z represents Atomic number
A represents Mass number
X represents the symbol of an element
Beta decay : In this process, a neutron gets converted into a proton and an electron releasing a beta-particle. The beta particle released carries a charge of -1 units.

The given reaction would be represented as:
