What is composed of atoms in fixed proportions?
A. mixtures
B. compounds
C. electrons
D. elements
chemistry-dictionary(dot)com/ is a great source.
d. Elements
The correct answer is B. compounds.
Compounds are substances that are composed of atoms of two or more different elements in fixed proportions. This means that the ratio of atoms in a compound is always the same, regardless of the amount of the compound present.
To determine the correct answer, you can break down the options:
A. Mixtures: Mixtures are composed of two or more substances that are physically combined but not chemically bonded together. The components of mixtures can vary in proportions.
B. Compounds: Compounds are substances composed of atoms of two or more different elements in fixed proportions, as explained above.
C. Electrons: Electrons are subatomic particles that orbit the nucleus of an atom, and they do not fit the description of being composed of atoms in fixed proportions.
D. Elements: Elements are pure substances made up of only one type of atom. While elements make up compounds, they themselves are not composed of atoms in fixed proportions.
Therefore, the correct answer is B. compounds.