Atomic Mass.

Slides:



Advertisements
Similar presentations
4.3: HOW ATOMS DIFFER ATOMIC NUMBER
Advertisements

Average Atomic Mass & % Abundance
Solving atomic calculations: Working with: – Elements – Isotopes – Ions – Atomic # – Atomic mass – Charge.
Atomic Structure Section The Nucleus Nucleus- contains most of the mass of an atom – Protons & Neutrons contains most of an atom’s mass – Electrons-
17.2 Masses of Atoms. Atomic Mass The nucleus contains most of the mass of the atom bc P and N are far more massive than E. P & N are about the same size.
Atomic Structure Nucleus – contains protons and neutrons
Atomic Mass & Number Isotopes The Periodic Table.
Mass Number Atomic Number equals the # of... NUCLEUS ELECTRONS PROTONS NEUTRONS NEGATIVE CHARGE POSITIVE CHARGE NEUTRAL CHARGE ATOM.
Section 2: Masses of Atoms
Chapter 18 Lesson 2 Masses of Atoms
Atomic Mass Notes 5 Chapter 17-2.
The Atom.
Ch. 11 Section 2 The Atom. Vocabulary To Know  Proton- subatomic particle that has a positive charge and that is found in the nucleus  Atomic mass unit-
Masses of Atoms Chapter 19-2 Pages
Isotopes and Average Atomic Mass Vocabulary: 1.isotope 2.percent abundance 3.average atomic mass “Marilyn Monroe”, Andy Warhol, 1962.
Atomic Mass. Masses in amu Only carbon-12 has an atomic mass exactly equal to its mass # One atomic mass unit (amu) is defined as 1/12 the mass of a carbon-12.
Chapter 1 Activity 9 Part A
Atoms & Their Structure Chapter 2 Section 1 Part 3.
Average Atomic Mass What is average atomic mass? Average atomic mass is the weighted average of the atomic masses of the naturally occurring isotopes of.
How Atoms Differ. a. Properties of Subatomic Particles ParticleSymbolLocationRelative Charge Relative mass Actual mass (g) Electron Proton Neutron.
 Nucleus contains most of the mass of the atom ◦ Protons and neutrons are far more massive than electrons ◦ Mass of a proton or neutron is approximately.
Note: When doing calculations never clear your calculator.
Atomic Mass. Atomic mass Most of the mass of an atom is in the nucleus. Most of the mass of an atom is in the nucleus. The nucleus is where all of the.
Daily Science Who discovered the electron and how did he discover it? What was his model called? What tells you the number of p + an element has? Write.
Masses of Atoms.
Section 2 Protons, neutrons, and electrons- how atoms differ
Ch. 3-3a Distinguishing and Counting Atoms
Calculating Average Mass
Warm Up Monday 1/25/16 1. What are atoms?
4.2 – NOTES The Mass of the Atom
4.2 -Atomic Structure Theory
Isotopes.
STRUCTURE OF THE ATOM.
ISOTOPES AVERAGE ATOMIC MASS
Atomic Particles Particle Charge Mass # Location Electron -1
Distinguishing Between Atoms
Atomic Structure.
Isotopes - isotope: atoms of the same element that have different numbers of neutrons - Carbon, as found in nature, is a mixture of isotopes, including.
INTRODUCTION TO ATOMS CHAPTER 3 section 1.
Structure of The Atom Not the Adam.
Atomic Structure Chemistry.
Section 1 Structure of the atom and cells on the periodic table
Foldables: Atoms Terms.
Mass of Individual Atoms
Isotopes QUICK NOTES Carbon-14
Isotope -an atom with a different number of NEUTRONS than protons.
Title: Atomic Properties
Intro to Atomic Structure
Isotopes Atoms with SAME number of PROTONS (atomic number) but DIFFERENT numbers of neutrons (i.e. mass number) 6 protons 6 neutrons 6 protons 7 neutrons.
Isotopes.
Atomic Structure Chemistry.
Ch. 3 - Atomic Structure II. Masses of Atoms (p.75-80) Mass Number
1. What are these two atoms of carbon called?
AVERAGE ATOMIC MASS CALCULATIONS
How We Know What We Can’t See Looks Like Day 4 Average Atomic Mass
ATOMIC STRUCTURE THE NUCLEUS: 1) THE PROTON:
The Atom.
Atomic Structure Protons- positively charged, found in nucleus
Atomic Structure Nucleons Atomic Number
Atomic Number, Mass Number, Atomic Mass and Isotopes
Section 2.1: The Nature of Matter Adapted from Teacher: Mrs. Rolle
The Atom.
Ch. 4 - Atomic Structure II. Masses of Atoms Mass Number Isotopes
How We Know What We Can’t See Looks Like Day 4 Average Atomic Mass
Atomic Structure Nucleus Protons Neutrons Electrons.
1. What are these two atoms of carbon called?
Introduction to Atomic Structure
Chapter 18 Lesson 2 Masses of Atoms
Section 2: Masses of Atoms
Counting Subatomic Particles
Presentation transcript:

Atomic Mass

Atomic Mass The nucleus contains most of the mass of the atom because protons and neutrons are far more massive than electrons. The mass of a proton is about the same as that of a neutron.

Atomic Mass The mass of each is approximately 1,800 times greater than the mass of the electron.

Atomic Mass The unit of measurement used for atomic particles is the atomic mass unit (amu). The mass of a proton or a neutron is almost equal to 1 amu. The atomic mass unit is defined as one-twelfth the mass of a carbon atom containing six protons and six neutrons.

Atomic Number The number of protons tells you what type of atom you have and vice versa. For example, every carbon atom has six protons. Also, all atoms with six protons are carbon atoms. The number of protons in an atom is equal to a number called the atomic number.

Mass Number The mass number of an atom is the sum of the number of protons and the number of neutrons in the nucleus of an atom.

Mass Number If you know the mass number and the atomic number of an atom, you can calculate the number of neutrons. number of neutrons = mass number – atomic number

Isotopes Not all the atoms of an element have the same number of neutrons. Atoms of the same element that have different numbers of neutrons are called isotopes.

Isotopes Models of two isotopes of boron are shown. Because the numbers of neutrons in the isotopes are different, the mass numbers are also different. You use the name of the element followed by the mass number of the isotope to identify each isotope: boron-10 and boron-11.

Identifying Isotopes The average atomic mass of an element is the weighted-average mass of the mixture of its isotopes. For example, four out of five atoms of boron are boron-11, and one out of five is boron-10. To find the weighted-average or the average atomic mass of boron, you would solve the following equation:

Section Check Question 1 How is the atomic number of an element determined? Answer The atomic number of an element is equal to the number of protons in an atom of that element.

Section Check Question 2 The element helium has a mass number of 4 and atomic number of 2. How many neutrons are in the nucleus of a helium atom?

Section Check Answer Recall that the atomic number is equal to the number of protons in the nucleus. Since the mass number is 4 and the atomic number is 2, there must be 2 neutrons in the nucleus of a helium atom.

Section Check Question 3 How much of the mass of an atom is contained in an electron? Answer The electron’s mass is so small that it is considered negligible when finding the mass of an atom.