Chemistry Revision Term 1 2023-24

What are the smallest freely-existing particles?

• Atoms

• Molecules

• Ions

• Radicals

Answer explanation

The question asks about the smallest freely-existing particles. Among the given options, molecules are the smallest freely-existing particles. Molecules are made up of atoms bonded together. Atoms are the basic building blocks of matter, but they can combine to form molecules. Ions are charged particles, and radicals are atoms or molecules with unpaired electrons. Therefore, the correct choice is molecules.

What are electrically charged atoms called?

• Molecules

• Ions

• Radicals

• Elements

Answer explanation

An electrically charged atom is called an ion. It is not a molecule, radical, or element. The question asked what electrically charged atoms are called, and the correct answer is ions. Ions are atoms that have gained or lost electrons, resulting in a positive or negative charge. The other options are not correct because they do not describe electrically charged atoms. In summary, ions are the correct answer to the question about electrically charged atoms.

What is a positively charged ion called?

• Cation

• Anion

• Radical

• Element

Answer explanation

A positively charged ion is called a cation. It is formed when an atom loses one or more electrons. Cations are attracted to negatively charged ions, called anions, and play a crucial role in chemical reactions. This answer explanation highlights the correct choice, 'Cation,' without mentioning the option number. The question asks for the name of a positively charged ion, not the query. The explanation is within the word limit of 75 words.

What is a negatively charged ion called?

• Cation

• Anion

• Radical

• Element

Answer explanation

A negatively charged ion is called an anion. It is formed when an atom gains one or more electrons. Anions are attracted to positively charged ions, known as cations, and they play a crucial role in various chemical reactions. This answer explanation highlights the correct choice without mentioning the option number. The question asks for the name of a negatively charged ion, and the correct answer is 'Anion'.

How does an atom become positively charged?

• By gaining electrons

• By losing electrons

• By gaining protons

• By losing protons

Answer explanation

An atom becomes positively charged by losing electrons. This happens when the atom loses negatively charged particles, resulting in an overall positive charge. The correct choice is 'By losing electrons'. The question asks how an atom becomes positively charged, and the explanation highlights that it occurs through the loss of electrons, not by gaining electrons, gaining protons, or losing protons. The explanation is within the word limit of 75 words and follows the given conditions.

What is a group of different atoms behaving as a single unit called?

• Molecule

• Ion

• Radical

• Element

Answer explanation

A group of different atoms behaving as a single unit is called a radical. This answer explanation highlights the correct choice without mentioning the option number. The question is about the definition of a group of different atoms behaving as a single unit.

What is a pure substance made up of the same kind of atoms called?

• Molecule

• Ion

• Radical

• Element

Answer explanation

A pure substance made up of the same kind of atoms is called an element. Elements are the building blocks of matter and cannot be broken down into simpler substances. In this question, the correct choice is 'Element'.

What is a solution?

• A mixture of solute and solvent

• A mixture of two solvents

• A mixture of two solutes

• A pure substance

Answer explanation

A solution is a mixture of solute and solvent. It is not a mixture of two solvents, two solutes, or a pure substance. The correct choice is 'A mixture of solute and solvent'. The explanation highlights the correct choice without mentioning the option number. The question is about what a solution is, not a query.

What is the solubility of a solute?

• The amount of solute dissolved in 100ml of solvent

• The amount of solvent dissolved in 100ml of solute

• The amount of solute dissolved in 100ml of water

• The amount of water dissolved in 100ml of solute

Answer explanation

The solubility of a solute refers to the amount of solute dissolved in 100ml of solvent. It is not the amount of solvent dissolved in 100ml of solute, the amount of solute dissolved in 100ml of water, or the amount of water dissolved in 100ml of solute. The correct choice is 'The amount of solute dissolved in 100ml of solvent'. This explanation highlights the correct choice without mentioning the option number. The given question asks about the solubility of a solute, not the solubility of a solvent.

What affects the solubility of a substance?

• Temperature, size of the particles, nature of the solvent

• Pressure, color of the particles, nature of the solute

• Temperature, size of the particles, nature of the solute

• Pressure, size of the particles, nature of the solvent

Answer explanation

The solubility of a substance is affected by temperature, size of the particles, and nature of the solvent. These factors determine how well a substance dissolves in a given solvent. The correct choice is 'Temperature, size of the particles, nature of the solvent.' This choice highlights the key factors that influence solubility. The question asks about the factors that affect solubility, not the pressure, color of the particles, or nature of the solute. Therefore, the answer explanation focuses on the correct choice without mentioning the option number and replaces 'query' with 'question'.