Exam: IELTS

Definition: A unit of measurement used to express the optical power of a lens or mirror, equal to the reciprocal of the focal length in meters.

Example: The optometrist measured my vision and prescribed glasses with a strength of +2.5 dioptres.

Definition: A clear, colorless liquid that can catch fire and is used to dissolve substances like fats and resins in products such as paints and cosmetics.

Example: Dioxane is often used in laboratories as a solvent for various chemical reactions.

Definition: A chemical compound made of one metal atom and two oxygen atoms.

Example: Carbon dioxide is a common example of a dioxid.

Definition: A chemical compound that has two oxygen atoms in each molecule.

Example: Carbon dioxide is produced when we breathe out.

Definition: A group of harmful chemical compounds that can cause cancer and birth defects, often found as pollutants from industrial processes and certain herbicides.

Example: Dioxins are dangerous pollutants that can accumulate in the food chain and pose serious health risks.

Definition: To lower or drop down slightly, often temporarily, or to sink out of sight suddenly.

Example: The sun dipped below the horizon, painting the sky with beautiful colors.

Definition: A quick immersion or plunge into a liquid, often for swimming or tasting food.

Example: She took a dip in the cool lake on a hot summer day.

Definition: To put something into a liquid for a short time, usually to cover it or change its color.

Example: She decided to dip the strawberries in chocolate before serving them.

Definition: A type of enzyme that helps break down dipeptides into individual amino acids.

Example: Dipeptidase is essential for protein digestion in the body.

Definition: A type of molecule made up of two amino acids connected together by a bond.

Example: Dipeptides are important in the study of protein structure and function.

Definition: A colorless solid chemical compound used in making dyes, plastics, and other products.

Example: Diphenylamine is often used as a stabilizer in the production of certain plastics.

Definition: A chemical compound that has two phosphate groups, often involved in biological processes.

Example: Adenosine diphosphate (ADP) is an important molecule in energy transfer within cells.