The total number of electrons present in 18 ml of water:

Water is composed of two hydrogen atoms and one oxygen atom. To determine the total number of electrons present in 18 ml of water, we need to consider the atomic structure of each element and their respective quantities in water.

1. Atomic structure of hydrogen:
- Hydrogen is the lightest element in the periodic table.
- It has an atomic number of 1, indicating that it has one proton and one electron.
- The atomic mass of hydrogen is approximately 1.008 amu (atomic mass unit).

2. Atomic structure of oxygen:
- Oxygen is the 8th element in the periodic table.
- It has an atomic number of 8, indicating that it has 8 protons and 8 electrons.
- The atomic mass of oxygen is approximately 16.00 amu.

3. Molecular formula of water:
- The molecular formula of water is H2O, indicating that it consists of two hydrogen atoms and one oxygen atom.
- This means that each water molecule contains a total of 10 electrons (2 from hydrogen and 8 from oxygen).

4. Calculation:
To determine the total number of electrons present in 18 ml of water, we need to consider the number of water molecules present in that volume. We can use the concept of molarity to calculate this.

- The molar mass of water (H2O) is approximately 18.015 g/mol.
- Given that the volume of water is 18 ml, we need to convert it to grams using the density of water, which is approximately 1 g/ml.
- Therefore, the mass of water in grams is 18 g.

Using the formula:
Number of moles = mass (g) / molar mass (g/mol)

- Number of moles of water = 18 g / 18.015 g/mol = 0.9996 mol

Now, to calculate the total number of water molecules:

- Number of water molecules = Number of moles × Avogadro's number
- Avogadro's number (NA) is approximately 6.022 × 10^23 mol^-1.

- Number of water molecules = 0.9996 mol × 6.022 × 10^23 mol^-1
- Number of water molecules = 6.020 × 10^23 molecules

Finally, to determine the total number of electrons:

- Total number of electrons = Number of water molecules × Number of electrons per molecule
- Number of electrons per molecule of water = 10 (as calculated earlier)

- Total number of electrons = 6.020 × 10^23 molecules × 10 electrons/molecule
- Total number of electrons = 6.020 × 10^24 electrons

Therefore, there are approximately 6.020 × 10^24 electrons present in 18 ml of water.

(0.018/22.4) × N molecules