Non living things are abiotic so sand is abiotic
Answer:
Option B is correct.
4
Explanation:
We know that an atom consist of electron, protons and neutrons. Protons and neutrons are present with in nucleus while the electrons are present out side the nucleus.
All these three subatomic particles construct an atom. A neutral atom have equal number of proton and electron. In other words we can say that negative and positive charges are equal in magnitude and cancel the each other. For example, if neutral atom has 6 protons than it must have 6 electrons. The sum of neutrons and protons is the mass number of an atom while the number of protons are number of electrons is the atomic number of an atom.
In given problem we are given with 2 neutrons of helium. We know that the atomic number of He is 2. Thus Mass number of He is,
Number of neutrons + number of proton
2 + 2 = 4
Thus, option B is correct.
Answer:
3 moles
Explanation:
To solve this problem we will use the Avogadro numbers.
The number 6.022×10²³ is called Avogadro number and it is the number of atoms, ions or molecules in one mole of substance. According to this,
1.008 g of hydrogen = 1 mole = 6.022×10²³ atoms.
18 g water = 1 mole = 6.022×10²³ molecules
we are given 36 g of C-12. So,
12 g of C-12 = 1 mole
24 g of C-12 = 2 mole
36 g of C-12 = 3 mole
So 3 moles of C-12 equals to the number of particles in 36 g of C-12.
