Question 2.1: Distinguishing Elements, Compounds, and Mixtures at the Atom......
Distinguishing Elements, Compounds, and Mixtures at the Atomic Scale
Problem The scenes below represent atomic-scale views of three samples of matter (Fig 2.1):
Describe each sample as an element, compound, or mixture.
Plan We have to determine the type of matter by examining the component particles. If a sample contains only one type of particle, it is either an element or a compound; if it contains more than one type, it is a mixture. Particles of an element have only one kind of atom (one color of sphere in an atomic-scale view), and particles of a compound have two or more kinds of atoms.
Solution (a) Mixture: there are three different types of particles. Two types contain only one kind of atom, either green or purple, so they are elements, and the third type contains two red atoms for every one yellow, so it is a compound.
(b) Element: the sample consists of only blue atoms.
(c) Compound: the sample consists of molecules that each have two black and six blue atoms.