isotopes:isotopes: atoms with the same number of protons but a different number of neutrons....
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2.1 Know the three basic subatomic particles of an atom and their charges: 1. Protons (+) 2. Electrons (-) 3. Neutrons (0)
2.2 Define
Atomic number (Z) Mass number (A) Use the notation, AZX to particular atoms
2.3 – Isotopes & Atomic Weights ▪ Define the word isotope and how it
relates to the number of neutrons of a particular type of atom
▪ Know the two conventions for writing isotopes
▪ Define the atomic weight of the average atom (what’s in the periodic table)
• Isotopes:Isotopes: atoms with the same number of protons but a different number of neutrons.– carbon-12 has 6 protons and 6 neutrons;– carbon-13 has 6 protons and 7 neutrons;– carbon-14 has 6 protons and 8 neutrons;
• Most elements found on Earth are mixtures of isotopes:– chlorine is 75.77% chlorine-35 (18 neutrons) and
24.23% chlorine-37 (20 neutrons).
C136C
136
C126C
126
C146C
146
• Mass number:Mass number: the number of protons and neutrons in the nucleus of an atom.– the mass of the electrons in an atom is so small
compared to that of its protons and neutrons that electrons are not counted in determining mass number.
• Atomic number:Atomic number: the number of protons in the nucleus of an atom.
• a carbon atom of this composition is referred to as carbon-12.
Mass number (number of protons & neutrons)Atomic number (number of protons)6
12C
• Atomic weight:Atomic weight: the weighted average of the masses (in amu) of the naturally occurring isotopes of an element.– example: chlorine is 75.77% chlorine-35 and
24.23% chlorine-37
75.77100
x 34.97 amu + 24.23100
x 36.97 amu = 35.45 amu
chlorine-35 chlorine-37 17Cl
35.4527
atomic weight in the Periodic Tableis given to four
four decimal places
EOC
2.3 Define and apply Atomic Mass Unit Know what is meant by Atomic Weight Know how to calculate percent abundances for elements with two isotopes
EOC
2.4 Know how to determine atomic weights - check
2.5 Be able to identify and locate the following features in the Periodic Table: 1) Metals & Nonmetals 2) Groups (both number systems)
(a) Main Group 1. Alkali Metals 2. Halogens 3. Noble Gasses 4. Alkali Earth Metals
(b) Transition Metals (c) Inner Transition Metals
3) Periods
EOC
EOC
2.6 & 2.7 1) Define, apply and distinguish among the terms: i) Element ii) Compound iii)Molecular Compound iv) Ionic Compound v) Formula
2.6 & 2.7 1) Understand the following features of Ionic
Compounds: i) General Composition
(a) Cation & Anion (b) Metal/Nonmetal (some exceptions)
ii) Monatomic Ions & the Periodic Table (a) M. Groups I & II metal cations (b) M. Groups V, VI & VII anions
iii) Polyatomic Ions – mostly anions (1) Memorize the name and formula for the
following (a) Ammonium, Acetate, Carbonate, Hydrogen
Carbonate, Nitrate, Sulfate, Phosphate, Hydroxide iv) Formulas
(1) Naming given formula (2) Writing formula given name
EOC
2.8 1) Learn to recognize, name and write formulas for one class of Molecular (Covalent) Compounds: Binary
a) Learn the guidelines 1. Put atoms in order of increasing group#
2. Prefixes for first atom Prefix Amount Di 2 Tri 3 Tetra 4 Penta 5 Hexa 6 Hepta 7 Octa 8 Nona 9 Deca 10
3. Prefixes for second atom Prefix Amount Mono 1 Di 2 Tri 3 Tetra 4 Penta 5 Hexa 6 Hepta 7 Octa 8 Nona 9 Deca 10
2.9 1. Understand and apply the Mole as a counting unit
2. Understand and apply, molar mass 3. Perform mole to mass and mass to
mole conversions for elements and compounds
EOC
EOC
2.10 1. Perform percent composition problems 2. Understand the term, Empirical Formula 3. Use percent composition to derive an
Empirical Formula 4. Use Empirical Formula and Molar Mass
to derive a Molecular Formula.
Empirical Formula
Molecular Formula is…
2.11 1. Understand & Recognize Hydrated Compounds
2. Determine the formulas of Hydrated Compounds
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