Topic: Symbols, Atomic Number and Atomic Mass Elements and Symbols Copyright © 2008 by Pearson Education, Inc. Publishing as Benjamin Cummings

Elements Elements are Pure substances that cannot be separated into simpler substances by ordinary laboratory processes. The building blocks of matter. gold carbon aluminum Copyright © 2008 by Pearson Education, Inc. Publishing as Benjamin Cummings

Sources of Some Element Names Some elements are named for planets, mythological figures, minerals, colors, scientists, and places. Table 4.1 Copyright © 2008 by Pearson Education, Inc. Publishing as Benjamin Cummings

Symbols of Elements A symbol Represents the name of an element. Consists of 1 or 2 letters. Has ONE capital letter. Examples: 1-Letter Symbols 2-Letter Symbols C carbon Co cobalt N nitrogen Ca calcium F fluorine Al aluminum O oxygen Mg magnesium

Symbols from Latin Names Several symbols are derived from Latin names as shown below: Cu, copper (cuprum) Au, gold (aurum) Fe, iron (ferrum) Ag, silver (argentum) Copyright © 2008 by Pearson Education, Inc. Publishing as Benjamin Cummings

Element Symbol/Name Quiz You will be required to memorize the name and symbol for 40 elements that are commonly used in this class. You will be quizzed one time each quarter. Highlight the elements on your periodic table.

11 Na Atomic Number Atomic Number Symbol The atomic number Is specific for each element. Is the same for all atoms of an element. Is equal to the number of protons in an atom…it is always a WHOLE NUMBER. Increases by 1 as you go left to right across the P. T. Atomic Number 11 Na Symbol

Atomic Numbers and Protons Examples: Hydrogen has atomic number 1, every H atom has one proton. Carbon has atomic number 6, every C atom has six protons. Copper has atomic number 29, every Cu atom has 29 protons. Gold has atomic number 79, every Au atom has 79 protons.

Atomic Models Copyright © 2008 by Pearson Education, Inc. Publishing as Benjamin Cummings

Learning Check State the number of protons in each. A. A nitrogen atom 1) 5 protons 2) 7 protons 3) 14 protons B. A sulfur atom 1) 32 protons 2) 16 protons 3) 6 protons C. A barium atom 1) 137 protons 2) 81 protons 3) 56 protons

Solution State the number of protons in each. A. A nitrogen atom 2) atomic number 7; 7 protons B. A sulfur atom 2) atomic number 16; 16 protons C. A barium atom, 3) atomic number 56; 56 protons

Electrons in An Atom An atom of any element is electrically neutral; the net charge of an atom is zero. In an atom, the number of protons is equal to the number of electrons. number of protons = number of electrons For example, an atom of aluminum has 13 protons and 13 electrons. The net charge is zero. 13 protons (13 +) + 13 electrons (13 -) = 0

Mass Number The mass number Represents the number of particles in the nucleus. Is equal to the Number of protons + Number of neutrons …must be a WHOLE NUMBER

Learning Check An atom of zinc has a mass number of 65. A. How many protons are in this zinc atom? 1) 30 2) 35 3) 65 B. How many neutrons are in the zinc atom? C. What is the mass number of a zinc atom that has 37 neutrons? 1) 37 2) 65 3) 67

Solution An atom of zinc has a mass number of 65. A. How many protons are in this zinc atom? 1) 30 (atomic number 30) B. How many neutrons are in the zinc atom? 2) 35 (65 – 30 = 35) C. What is the mass number of a zinc atom that has 37 neutrons? 3) 67 (30 + 37 = 67)

Learning Check An atom has 14 protons and 20 neutrons. A. Its atomic number is 1) 14 2) 16 3) 34 B. Its mass number is C. The element is 1) Si 2) Ca 3) Se

Solution An atom has 14 protons and 20 neutrons. A. It has atomic number 1) 14 B. It has a mass number of 3) 34 (14 + 20 = 34) C. The element is 1) Si (Atomic number 14)

Topic: The Periodic Table

Groups and Periods On the periodic table, Elements are arranged ….. By Atomic # According to similar properties. Groups/ Families contain elements with similar properties in vertical columns (↕). There are 18. Periods are horizontal rows of elements (↔). There are 7.

Groups and Periods Copyright © 2008 by Pearson Education, Inc. Publishing as Benjamin Cummings

Periodic Table

Group (↕) Numbers Group Numbers –You may see them represented 2 different ways: 1st way: Use a number with the letter A for the representative elements (main group elements) 1A to 8A ; the letter B for the transition elements. Representative elements are found in the taller sections on the left and right of the table…called "representative" because they have traits that represent the group they are in. Transition elements are in the middle, lower section of the table. ..called this because they are in the region that transitions from left to right side. 2nd way (what we will use): columns numbered from 1 to 18 going left to right

Names of Some Representative Elements Several groups of representative elements are known by common names.

Alkali Metals Soft, shiny, good electrical/heat conductors Group 1, the alkali metals, includes lithium, sodium, and potassium. Soft, shiny, good electrical/heat conductors React vigorously with water React with oxygen Are so reactive they are not found in nature…usually in a compound with another element Copyright © 2008 by Pearson Education, Inc. Publishing as Benjamin Cummings

Halogens Group 17, the halogens, includes chlorine, bromine, and iodine. Strong reactors with most other elements! Also unusual to find in nature as elements Copyright © 2008 by Pearson Education, Inc. Publishing as Benjamin Cummings

Noble Gases Group 18, the noble gasses include.. Inert (unreactive) Helium Neon Argon Inert (unreactive)

Learning Check Identify the element described by the following: A. Group (17), Period 4 1) Br 2) Cl 3) Mn B. Group (2), Period 3 1) beryllium 2) magnesium 3) boron C. Group (15), Period 2 1) phosphorus 2) arsenic 3) nitrogen

Solution A. Group (17), Period 4 1) Br B. Group (2), Period 3 2) magnesium C. Group (15), Period 2 3) nitrogen

Metals, Nonmetals, and Metalloids—where are they? The heavy zigzag line separates metals and nonmetals. Metals are located to the left. Nonmetals are located to the right. Metalloids are located along the heavy zigzag line between the metals and nonmetals. Copyright © 2008 by Pearson Education, Inc. Publishing as Benjamin Cummings

Properties of Metals, Nonmetals, and Metalloids Magnetic Shiny and ductile/malleable. Good conductors (heat and electricity). Nonmetals Non-magnetic Dull, brittle, and poor conductors. Good insulators. Metalloids Have properties of both Metals and Nonmetals Do not conduct electricity/heat as well as Metals. Used as semiconductors and insulators.

Comparing a Metal, Metalloid, and Nonmetal

Learning Check Identify each of the following elements as 1) metal 2) nonmetal 3) metalloid A. sodium ____ B. chlorine ____ C. silicon ____ D. iron ____ E. carbon ____

Solution Identify each of the following elements as 1) metal 2) nonmetal 3) metalloid A. sodium 1 metal B. chlorine 2 nonmetal C. silicon 3 metalloid D. iron 1 metal E. carbon 2 nonmetal

Learning Check Match the elements to the description: A. Metals in Group (14) 1) Sn, Pb 2) C, Si 3) C, Si, Ge, Sn B. Nonmetals in Group (15) 1) As, Sb, Bi 2) N, P 3) N, P, As, Sb C. Metalloids in Group (14) 1) C, Si, Ge, 2) Si, Ge 3) Si, Ge, Sn, Pb

Solution Match the elements to the description: A. Metals in Group (14) 1) Sn, Pb B. Nonmetals in Group(15) 2) N, P C. Metalloids in Group (14) 2) Si, Ge