Explanation

When the 6d orbital is completely filled, the next electron enters the 7p orbital.

This is based on the Aufbau principle, which dictates that electrons first occupy the lowest energy levels available.

After the 6d orbitals (which can hold up to 10 electrons) are filled, 

The 7p orbitals (which can hold up to 6 electrons) become the next lowest energy

Explanation

The Pfund series of hydrogen spectral lines occurs when electrons fall to the n = 5 energy level from higher levels.

These transitions emit radiation in the infrared (IR) region of the electromagnetic spectrum.

Explanation

Aluminum sulphate (also called alum) is a common coagulant used to purify potable water by causing suspended impurities to clump together and settle.

It helps remove particles, bacteria, and organic matter by forming flocs during the coagulation-flocculation process.

Explanation

In forming H2CO3 (carbonic acid), each oxygen atom utilizes sp2 hybrid orbitals.

Explanation

A neutral sodium atom (Na) has 11 electrons.

Na⁺ loses 1 electron, so it has 10 electrons.

Explanation

Molten NaCl conducts electricity.

Because it contains free-moving Na⁺ and Cl⁻ ions.

Explanation

To calculate the work done during the expansion of an ideal gas, we can use the formula for work done by a gas in an isobaric (constant pressure) process:

Explanation

The capacitance between two parallel charges sheets is dependent upon surface area and distance between the plates.

Capacitance of a parallel plate capacitor depends on the dielectric constant of the medium between the plates, area of each plate and distance between the plates.

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Explanation

The correct answer is: No change in composition

• A chemical change involves a transformation of one or more substances into new substances, which means a change in composition.

The signs of chemical change:

• Release of gas
• Change in color
• Change in temperature
• Change in smell
• Production of a new material

Explanation

The atomic mass (A) is the sum of protons and neutrons in the nucleus. In this case:

• Protons (Z) = 11
• Neutrons (N) = 12
• Atomic Mass (A) = Z + N = 11 + 12 = 23