The question asks for the scientific definition of "matter." To answer this, we need to recall the fundamental properties that define matter in physics and chemistry.
D) Has mass and occupies space (volume) — This is the universally accepted scientific definition of matter. Anything that has mass and takes up space is considered matter. This includes solids, liquids, gases, and plasma.
The question asks about the fundamental composition of matter. This requires knowledge of basic chemistry and physics principles regarding the structure of substances.
B) Atoms and molecules
All matter, whether solid, liquid, or gas, is ultimately composed of atoms. These atoms can exist individually (like noble gases) or combine to form molecules (like water \(\text{H}_2\text{O}\) or oxygen \(\text{O}_2\)). Therefore, atoms and molecules are the fundamental building blocks of matter.
The question asks for the smallest particle of an element that retains its chemical properties and can participate in a chemical reaction. This is a fundamental definition in chemistry.
Correct Option: A) An atom is the smallest particle of an element that can take part in a chemical reaction while still retaining the chemical properties of that element. For example, a single atom of oxygen still behaves chemically as oxygen, but if it's broken into protons, neutrons, and electrons, it no longer is oxygen.
The question asks for the best definition of a molecule. To answer this, we need to recall the fundamental definitions of chemical substances and their components. We will evaluate each option against the standard scientific definition of a molecule.
C) A group of two or more atoms chemically bonded together, representing the smallest unit of a substance that can exist independently while retaining its chemical properties. This option provides a comprehensive and accurate definition of a molecule, encompassing its composition (two or more atoms), the nature of their association (chemically bonded), and its fundamental role as the smallest independent unit retaining chemical properties.
The question asks for the best definition of an element. We need to recall the fundamental definition of an element in chemistry and evaluate each option against this definition.
Correct Option: B) Consists of only one type of atom and cannot be broken down into simpler substances by ordinary chemical methods
This option accurately defines an element. An element is fundamentally characterized by having only one type of atom (defined by its atomic number, i.e., number of protons) and its inability to be decomposed into simpler substances through chemical reactions.
The question asks for the best definition of a compound. We need to evaluate each option based on the fundamental chemical principles that distinguish compounds from mixtures and elements.
A) Two or more different elements chemically combine together in a fixed, definite proportion. This is the precise definition of a chemical compound. The chemical bonding creates new substances with distinct properties, and the fixed proportion ensures a consistent composition.