Explanation

• Transition elements, also known as transition metals, are a group of elements in the d-block of the periodic table.
• They are characterized by their ability to form ions with different charges.
• They are often found in the middle of the periodic table.

Explanation

• The mass number (represented by the letter A) is defined as the total number of protons and neutrons in an atom.
• Consider the table below, which shows data from the first six elements of the periodic table.
• Consider the element helium.
• Its atomic number is 2, so it has two protons in its nucleus.

Explanation

The ratio of hydrogen to oxygen by mass in water is always 1:8. 

This ratio is derived from the atomic masses of hydrogen (approximately 1 g/mol) and oxygen (approximately 16 g/mol) in the water molecule (H₂O),

Where there are two hydrogen atoms and one oxygen atom.

Therefore, the mass ratio is (2 * 1) : 16, which simplifies to 2:16 or 1:8. 

Explanation

Stoichiometry calculations can only be carried out when all of the above are true:

Irreversible reactions:

Stoichiometry calculations are based on the assumption that the reaction proceeds to completion, meaning all reactants are used up to form products. 

No side reactions:

Side reactions would introduce additional products and complicate the calculations. 

At least one reactant consumed completely:

Stoichiometry calculations determine the amount of products formed based on the amount of a limiting reactant. 

Explanation

Spectroscopy is a analytical technique used to measure the interaction between matter and electromagnetic radiation, such as light.

It is used to assess the concentration or amount of a given atomic, molecular, or ionic chemical species by measuring the absorption, emission, or scattering of light by the species.

Explanation

Starch is a polysaccharide, a long chain of glucose molecules linked together through glycosidic bonds.

It is a complex carbohydrate that serves as a energy storage molecule in plants.

Explanation

Acids are known to cause corrosive effects on skin, including burns, ulcers, and damage to skin tissue.

Examples of corrosive acids include sulfuric acid (H2SO4), hydrochloric acid (HCl), and nitric acid (HNO3).

Explanation

• When a saturated solution of KCl (potassium chloride) is heated, the solubility of KCl increases, allowing more KCl to dissolve in the solution.
• If the solution is heated to a temperature where all the KCl dissolves, it becomes a supersaturated solution.
• A supersaturated solution contains more dissolved solute than it can hold at a given temperature, making it unstable.

Explanation

• A triple covalent bond is a chemical bond that involves the sharing of three pairs of electrons between two atoms.
• This type of bond is typically found in molecules where three pairs of electrons are shared, resulting in a strong and stable bond.

Explanation

• Heat is a form of energy that flows from a region of high temperature to a region of low temperature.
• This flow of energy occurs through the transfer of kinetic energy from particles in motion.