MCQs

Explanation
The charges of  Proton, Electron, Neutron  respectively are: Proton:  Positive  charge (+1) Electron:  Negative  charge (-1) Neutron:  Neutral  charge (0)

Explanation
Benzene is more volatile because it has a low boiling point and evaporates quickly at room temperature. Volatility refers to a liquid's tendency to vaporize — benzene does so more readily than the others listed.

Explanation
Methanol (CH₃OH) is polar due to the presence of the highly electronegative –OH group and its bent geometry. Other molecules like CO₂ and CCl₄ are non-polar because of their symmetrical shape, despite having polar bonds.

Explanation
Isotopes are atoms with different atomic masses that have the same atomic number. The atoms of different isotopes are atoms of the same chemical element ; they differ in the number of neutrons in the nucleus. Isotopes: The isotopes are a group of atoms that have the same atomic numbers but different mass numbers. That means all isotopes of an element have the same number of protons in their atomic nuclei and the same number of electrons in the electron cloud surrounding the nucleus. Difference between isotopes Isotopes differ in the total number of neutrons present in their respective atomic nuclei. Thus they have different mass numbers. Different isotopes of the same element are having different masses. Protium (1 proton,1 electron, and no neutrons), Deuterium (1 proton, 1 electron, and 1 neutron), and Tritium (1 proton, 1 electron, and 2 neutrons) are examples of isotopes of Hydrogen.

Explanation
1 radian ≈ 57.3 degrees , based on the formula:  1 radian = 180/𝜋 degrees . It is a standard angular measurement in mathematics and physics .

Explanation
Gold has the symbol Au . It has the atomic number 79. This making it one of the higher atomic number elements found in nature.

Explanation
Step 1: Let's denote the two numbers as x and y.
We have two equations:
1. x + y = 28
2. x - y = 4

Step 2: Solve the system of equations.
Adding the two equations eliminates y:
(x + y) + (x - y) = 28 + 4
2x = 32
Step 3: Solve for x.
x = 32 / 2
x = 16
Step 4: Solve for y.
Substitute x into one of the original equations:
16 + y = 28
y = 28 - 16
y = 12
Step 5: Identify the correct pair of numbers.
The numbers are 16 and 12.

Explanation
Total parts = 6 + 4 = 10; each part = 1300 ÷ 10 = Rs. 130 Smallest part = 4 × 130 = Rs. 520

Explanation
Chromosomes are thread-like structures made of DNA and proteins , found in the nucleus of eukaryotic cells. They carry genetic information and ensure its accurate distribution during cell division .

Explanation
Reproduction ensures the continuation of a species by passing genetic material to offspring. It maintains biodiversity and helps species adapt to environmental changes.

Explanation
The charges of  Proton, Electron, Neutron  respectively are: Proton:  Positive  charge (+1) Electron:  Negative  charge (-1) Neutron:  Neutral  charge (0)

Explanation
Benzene is more volatile because it has a low boiling point and evaporates quickly at room temperature. Volatility refers to a liquid's tendency to vaporize — benzene does so more readily than the others listed.

Explanation
Methanol (CH₃OH) is polar due to the presence of the highly electronegative –OH group and its bent geometry. Other molecules like CO₂ and CCl₄ are non-polar because of their symmetrical shape, despite having polar bonds.

Explanation
Isotopes are atoms with different atomic masses that have the same atomic number. The atoms of different isotopes are atoms of the same chemical element ; they differ in the number of neutrons in the nucleus. Isotopes: The isotopes are a group of atoms that have the same atomic numbers but different mass numbers. That means all isotopes of an element have the same number of protons in their atomic nuclei and the same number of electrons in the electron cloud surrounding the nucleus. Difference between isotopes Isotopes differ in the total number of neutrons present in their respective atomic nuclei. Thus they have different mass numbers. Different isotopes of the same element are having different masses. Protium (1 proton,1 electron, and no neutrons), Deuterium (1 proton, 1 electron, and 1 neutron), and Tritium (1 proton, 1 electron, and 2 neutrons) are examples of isotopes of Hydrogen.

Explanation
1 radian ≈ 57.3 degrees , based on the formula:  1 radian = 180/𝜋 degrees . It is a standard angular measurement in mathematics and physics .

Explanation
Gold has the symbol Au . It has the atomic number 79. This making it one of the higher atomic number elements found in nature.

Explanation
Step 1: Let's denote the two numbers as x and y.
We have two equations:
1. x + y = 28
2. x - y = 4

Step 2: Solve the system of equations.
Adding the two equations eliminates y:
(x + y) + (x - y) = 28 + 4
2x = 32
Step 3: Solve for x.
x = 32 / 2
x = 16
Step 4: Solve for y.
Substitute x into one of the original equations:
16 + y = 28
y = 28 - 16
y = 12
Step 5: Identify the correct pair of numbers.
The numbers are 16 and 12.

Explanation
Total parts = 6 + 4 = 10; each part = 1300 ÷ 10 = Rs. 130 Smallest part = 4 × 130 = Rs. 520

Explanation
Chromosomes are thread-like structures made of DNA and proteins , found in the nucleus of eukaryotic cells. They carry genetic information and ensure its accurate distribution during cell division .