Explanation

• Electronic configuration refers to the distribution of electrons within an atom or molecule.
• It shows how the electrons are arranged in different energy levels (shells) and sublevels (orbitals) around the nucleus.

Explanation

• Carbon-12 (C-12) is the most abundant of the two stable isotopes of carbon, amounting to 98.93% of elemental carbon on Earth.
• Carbon-12 is composed of six protons, six neutrons, and six electrons.
• The atomic mass of carbon-12 is exactly 12 Dalton's, by definition.

Explanation

• The nucleon number (mass number) of Potassium is 39, and the atomic number (number of protons) is 19.
• To find the number of neutrons, subtract the number of protons from the nucleon number:
• 39 (nucleon number) - 19 (proton number) = 20
• So, the number of neutrons in Potassium-39 is 20.

Explanation

• The atomic number 19 corresponds to the element Potassium (K).
• The electron configuration of Potassium is: 1s² 2s² 2p⁶ 3s¹
• Which can be simplified to: 2, 8, 8, 1.

Explanation

• The number of protons and neutrons in an atom are added together to obtain the total number of nucleons.
• It is also known as the mass number.

Explanation

• A substance is a piece of matter in pure form, with a specific composition and properties.
• It can be either an element or a compound.

Explanation

• The empirical formula of hydrogen peroxide (H2O2) is HO.
• The empirical formula is the simplest whole-number ratio of atoms of each element in a compound.
• In this case, the ratio of hydrogen to oxygen is 1:1, which is represented by the formula HO.

Explanation

• H2 is only a homo atomic [homo: same] molecule.
• Rest three are hetero atomic [hetero: different] molecules).

Explanation

• Ethyl alcohol was prepared by Al-Razi (also known as Rhazes).
• He was a Persian polymath who made significant contributions to chemistry and medicine, including the distillation of alcohol.

Explanation

• A molecular formula is a chemical formula that shows the actual number and type of atoms in a molecule.
• It is a way to represent the composition of a molecule using symbols and numbers.

For example:

• Water: H2O (two hydrogen atoms and one oxygen atom)