Relative Atomic Mass Mass of atoms is incredibly small! So we have to use relative atomic mass. The symbol for relative atomic mass is Ar Carbon- 12 atom.

Slides:

Advertisements

Similar presentations

4.3: HOW ATOMS DIFFER ATOMIC NUMBER

Advertisements

Key thing to remember: The proton number is what defines an element, if that changes it becomes a different element! Isotopes and Relative Atomic Mass.

Average Atomic Mass & % Abundance

Understanding Chemical Reactions Lesson 1. Lesson Objectives Ensure familiarity with concept of atomic structure. Understand what isotopes are. Understand.

Atomic Structure Nucleus – contains protons and neutrons

Chapter 11B Notes Determining Isotope Masses. Intro What is the mass of an atom with 6 protons and 6 neutrons? 12 What is the mass of an atom with 6 protons.

ISOTOPIC NOTATION isotopes are atoms with the same number of protons but different number of neutrons A Z X A = mass number (the total number of protons.

OF PROTONS, NEUTRONS AND ELECTRONS IN AN ATOM

Atoms: The building blocks of Matter

Examples: Average Atomic Mass. Example Chlorine exists as a mixture of % chlorine-35 and % chlorine-37. Determine the average atomic mass.

Dalton was proved incorrect and his theory was modified

Mass Number Atomic Number equals the # of... NUCLEUS ELECTRONS PROTONS NEUTRONS NEGATIVE CHARGE POSITIVE CHARGE NEUTRAL CHARGE ATOM.

Isotopes Atoms of the same element that different mass numbers

Atomic Number, Mass Number, Atomic Mass and Isotopes

Counting Atoms 3.3. Counting Atoms Very difficult to count Atomic Number – # of p + of each atom of that element Whole numbers Elements arranged by atomic.

Radioactive Decay What happens to the nucleus of an atom when it emits a radiation? Starter: Think about the reaction between Mg and O  BRIGHT WHITE LIGHT.

Isotopes  Atoms with the same number of protons but different numbers of neutrons  Ex) Carbon 12 vs. Carbon 14  These atoms have a different mass 

More about isotopes Atomic mass vs average atomic mass or atomic weight.

 Atomic Number- the number of protons in the nucleus of an atom of that element  Ex: Hydrogen atoms have only one proton in the nucleus, so the atomic.

Subatomic Particles. Atomic Particles ParticleChargeMass (kg)Location Electron9.109 x Electron cloud Proton x Nucleus Neutron

Ch. 3 - Atomic Structure II. Masses of Atoms (p.75-80)  Mass Number  Isotopes  Relative Atomic Mass  Average Atomic Mass.

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.

Isotopic Abundance SCH 3U. Atomic Mass The mass of an atom (protons, neutrons, electrons) Relative Atomic Mass: An element’s atomic mass relative to the.

Section 4.3 How atoms differ. Atomic Number Represents three things in a neutral atom: 1. What element it is 2. The number of protons in each atom 3.

Average Atomic Mass. Relative Atomic Masses  Masses of atoms (in grams) are very small, so for convenience we use relative masses.  Carbon-12 is our.

Atomic Number & Atomic Mass

Atomic Structure The Periodic Table, Isotopes, and Average Atomic Mass.

Isotopes. The Nucleus  The number of protons in the nucleus of an atom is unique to each type of element  BUT, the nuclei of the same type of element.

Note: When doing calculations never clear your calculator.

Chapter 3 Isotopes Part II. Atoms Nucleus is center core. Nucleus is center core. Nucleus is made of Protons & Neutrons. Nucleus is made of Protons &

29 February 2016 Today’s Title: CW: Isotops Learning Question: What is an isotope ? Starter – ms-and-isotopes/10662.html.

Atomic Number & Mass Number All atoms consist of protons and electrons- most also have neutrons Protons & neutrons- in the small dense nucleus- similar.

Isotopes. What is an isotope? Not all atoms of an element are identical. Some elements have isotopes. Isotopes (iso means “same”) are atoms with the same.

Atomic Structure and Isotopes. Recap: Atomic Structure An atom is the simplest form of an element that can take part in a chemical reaction Three subatomic.

Isotopes and abundance. The relative atomic mass scale is now based on an isotope of carbon, carbon-12, which is given the value of amu.

4.3 Atomic #, Mass #, Atomic Mass & Isotopes. Atomic Number  What are the 3 subatomic particles?  Which of the subatomic particles identifies an element?

3.3: Counting Atoms How do I count and calculate the mass of atoms?

Bellwork Friday, 10/9 Find your notes on isotopes. At the top of pg. 2: Fill in the following… Finish this and we’ll check it.

Same Element Different Atom- Isotopes All atoms of a particular element are not exactly alike. Some elements have atoms with different masses (isotopes)

Isotopes are atoms of the same element that have a different number of neutrons For example, Hydrogen has 3 isotopes: Protium (0 neutrons) Deuterium (1.

What is an ISOTOPE? EXAM PRACTICE

SNC1D Isotopes.

Calculating Atomic Mass

Average Atomic Mass In nature, most elements are a mixture of different isotopes The mass of a sample of an element is a weighted average of all the isotopes.

Calculating Average Mass

4.2 – NOTES The Mass of the Atom

4.2 -Atomic Structure Theory

Starter - Calculate the P,N + E

Atomic Structure.

Isotopes and RAM Learning Outcomes:

Counting Atoms Section 3.3.

Unit 2: Atomic Theory & Structure

The atom and Isotopes.

Distinguishing Between Atoms

4.2 Periodic Table Squares and Average Atomic Mass

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.

Atomic Symbols = = mass # atomic # protons + neutrons protons

1. What are these two atoms of carbon called?

Atomic Number, Mass Number, Atomic Mass and Isotopes

Unit 1: Safety & Atomic Concepts

More about Elements.

1. What are these two atoms of carbon called?

Introduction to Atomic Structure

ARE ALL ATOMS OF THE SAME ELEMENT IDENTICAL?

Atomic Particles Particle Charge Mass (kg) Location Electron -1

Presentation transcript:

Relative Atomic Mass Mass of atoms is incredibly small! So we have to use relative atomic mass. The symbol for relative atomic mass is Ar Carbon- 12 atom contains 6 protons, 6 neutrons and 6 elections. Its relative atomic mass is defined as exactly 12. Every other atom is compared to this. E.g Helium is one 3 rd of a carbon atom. So its relative atomic mass is 4.

Calculate the relative atomic masses of an element using masses and abundance (A/A*) The relative atomic mass of bromine is 80 This is because in any sample of bromine, there are just about equal numbers of its two isotopes 79Br and 81Br. So the ‘average’ bromine atom has a relative mass of 80.

What about Chlorine and Copper? Chlorine has two isotopes Copper has two main isotopes Chlorine 3575% 3725% Copper 6369% 6531%

Finding the RAM of Chlorine If you assume you have 100 atoms then the average is easier to find

Finding the RAM of Chlorine You have 75 atoms of chlorine-35 and 25 atoms of chlorine

Finding the RAM of Chlorine That’s a mass of 75 x 35 and 25 x 37 To give the mass of the 100 atoms

Using Weighted Averages So the average mass of a chlorine atom isn’t (35+37)/2 Its (35 x 75) + (37 x 25)

From Weighted Averages to RAM Weighted = ( mass x number ) + ( mass x number ) ave total number So RAM = (35 x 75) + (37 x 25) 100 RAM = ( )/100 RAM = 35.5 amu

Weighted Averages Use RAM = (mass no x %) + (mass no x %) 100 To work out the RAM of Copper

RAM of copper RAM = (mass no x %) + (mass no x %) 100 So RAM = (63 x 69) + (65 x 31) 100 RAM = ( )/100 RAM = 63.6 amu

Here are various Isotopes- Attempt to calculate the number of electrons neutrons and protons for each. C – 12 C- 14 He – 4 He- 5 Li – 7 Li- 6

Isotopes Isotopes are atoms of the same element with different numbers of neutrons. That is; Same Atomic Number Same no. of protons Different Mass Number Different no. of neutrons Define an isotope in your own words before your see my definition

Watch the clip and answer the questions!

Isotopes of hydrogen IsotopeSymbolPNE Protium 101 Used as fuel, for hardening margarine. Deuteriu m 111 Used in heavy or deuterated water, solvent Tritium 121 Radioactive, Used in H-bombs, glow in the dark paints

Isotopes of hydrogen ProtiumDeuterium Tritium 1 proton, 0 neutron, 1 electron 1 proton, 1 neutron, 1 electron 1 proton, 2 neutron, 1 electron

Isotopes Element Symbo l Mass No Atomic No ProtonsNeutrons Electron s Chlorine-35Cl3517 Chlorine-37Cl3717 Copper-63Cu6329 Copper-65Cu6529 Bromine-79Br7935 Bromine-81Br8135 Objective check -