Answer:
V = 5 cm³
ρ = 4 g/cm³
Explanation:
Step 1: Calculate the volume (V)
We have a wooden cuboid of dimensions 5 cm × 1 cm × 1 cm. We can calculate its volume using the following expression.
V = 5 cm × 1 cm × 1 cm
V = 5 cm³
Step 2: Calculate the density (ρ)
The density is equal to the mass divided by the volume.
ρ = m / V
ρ = 20 g / 5 cm³
ρ = 4 g/cm³
Answer:
a) Cl, 17 protons and 17 electrons
Explanation:
The elements of group 17 are called halogens. These are six elements Fluorine, Chlorine, Bromine, Iodine, Astatine. The atomic number of chlorine is 17. Its means it has 17 protons and 17 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. Thus the atomic mass of chlorine will be 17+18 = 35 amu
Number protons = 17
Number of electrons = 17
Number of neutrons = 18
Properties of Chlorine:
1. it is greenish-yellow irritating gas.
2. its melting point is 172.2 K
3. its boiling point is 238.6 K
4. it is disinfectant and can kill the bacteria.
5. it is also used in manufacturing of paper, paints and textile industries.
First, we need to calculate the principal quantum number n for this electron, using the equation:
E = (-13.60 eV) / (n x n)
where E is the energy that is used to bound the electron (here, E = - 0.544 eV).
- 0.544 eV = (-13.60 eV) / (n x n)
n x n = (- 13.60 eV) / (- 0.544 eV)
n x n = 25
n = 5
The orbital radius that is equal to the radius of a hydrogen atom is calculated using the equation:
r = 0.053 nm x n x n
r = 0.053 nm x 5 x 5
r = 0.053 nm x 25
r = 1.325 nm
Well the width is 0.20 meters. Since there are a hundred centimeters in a meter, we just have to move the decimal point two times to the right to get a 20 centimeter width.
