Explanation

• Wavelength is the distance between two consecutive points on a wave that are in phase.
• It is typically denoted by the symbol λ (lambda).

Key Points:

• Time period (T) is the time taken by the wave to complete one oscillation.
• Frequency (f) is the number of oscillations per unit time.
• Amplitude (A) is the maximum displacement of the wave from its equilibrium position.

Explanation

Sodium carbonate is also known as washing soda.

It is commonly used to remove permanent hardness from water.

It reacts with calcium and magnesium ions, which are the causes of permanent hardness, to form precipitates that can be removed from the water.

Explanation

The bottom of the stratosphere is around 10 km (6.2 miles or about 33,000 feet) above the ground at middle latitudes.

The top of the stratosphere occurs at an altitude of 50 km (31 miles).

Explanation

Amphoteric substances are those that can react with both acids and bases.

They can donate or accept protons (H+ ions), depending on the conditions.

Examples of amphoteric substances include water (H2O), amino acids, and certain metals like zinc and aluminum.

Explanation

Nitrification is the process by which nitrogenous compounds in living organisms, such as ammonia (NH3), are converted into nitrates (NO3-) by microorganisms like bacteria.

This process occurs in soil, water, and the gut of animals, and is an essential step in the nitrogen cycle.

Explanation

Ligaments are bands of tough, fibrous, connective tissue that connect bones to each other at joints, providing stability and support.

They are essential for maintaining joint integrity and preventing excessive movement.

Explanation

Nuclear fission is a process in which a heavy, unstable nucleus splits into two or more smaller nuclei, releasing energy and often additional particles like neutrons.

This process is the opposite of nuclear fusion, where smaller nuclei combine to form a heavier nucleus.

Explanation

Question: A powder contains 100mg of a radioactive material that emits α-particles. The half-cycle of the isotope is five days. The mass of isotope that remains after ten days will be?

Answer: The half-life of the isotope is 5 days, which means that every 5 days, half of the remaining material decays. After 10 days, there will be two half-lives:

1. First half-life (5 days): 100mg → 50mg (half of the material decays)
2. Second half-life (next 5 days): 50mg → 25mg (half of theq remaining material decays)

So, after 10 days, 25mg of the original 100mg will remain.

Explanation

The symbol Z represents the proton number.

It is also known as the atomic number, which defines the element.

The symbol A represents the mass number (protons + neutrons).

Explanation

The electrostatic force between two electrons is F Newton, and since protons have the same charge magnitude as electrons (but opposite sign).

The force between two protons at the same distance is also F Newton.