CHAPTER 2 MATTER

Chapter 2.1 Objectives What is the difference between an element and a compound? Before: After: How are pure substances different from mixtures? Give 2 examples of a Homogeneous mixture and 2 examples of a Heterogeneous mixture? Write the name of the element for the following symbols: Hg, F, Pb, and C.

2.1 Classifying Matter? Matter is anything that: a) has mass, and b) takes up space Mass = a measure of the amount of “stuff” (or material) the object contains (don’t confuse this with weight, a measure of gravity) Volume = a measure of the space occupied by the object Everything is made of matter. Elements are made out of atoms. Carbon is an element. Diamonds are made of atoms of the element Carbon.

The elements that are most abundant on Earth are shown below.

Human Body Elements

Pure Substances: Elements and Compounds Matter that always has the same composition is classified as a pure substance, or simply a substance. Table Salt and Sugar Substances can be classified into 2 categories: elements and compounds. An element has a fixed composition because it contains only one type of atom.

Pure Substances: Elements and Compounds Elements- simplest kind of matter ; cannot be broken down any simpler ; all one kind of atom. Many familiar substances, such as aluminum and iron, are elements. Two or more elements combine chemically to make a compound.

Elements and Compounds Other substances are compounds, such as Nylon. The basic unit that makes up nylon contains carbon, hydrogen, nitrogen, and oxygen atoms. Every compound is unique and is different from the elements it contains. Compounds are substances that can be broken down only by chemical methods When broken down, the pieces have completely different properties than the original compound.

Elements and Compounds Made of two or more atoms, chemically combined (not just a physical blend!) Compounds can be broken down into simpler substances by chemical means, but elements cannot. Currently, there are 118 elements Elements have a 1 or two letter symbol, and compounds have a formula.

Elements and Compounds An element’s first letter always capitalized; if there is a second letter, it is written lowercase: B, Ba, C, Ca, H, He Start learning the elements names and symbols for the first 36 elements, along with Ag, Au, I, Pb, Sn, Hg, Zr, Xe, and Pt. Some names come from Latin or other languages.