Presentation is loading. Please wait.

Presentation is loading. Please wait.

ATOMIC STRUCTURE.

Published byFranklin Tyler Modified over 6 years ago

Similar presentations

Presentation on theme: "ATOMIC STRUCTURE."— Presentation transcript:

1 ATOMIC STRUCTURE

2 (greek for indivisible)
HISTORY OF THE ATOM Democritus develops the idea of atoms 460 BC he pounded up materials in his pestle and mortar until he had reduced them to smaller and smaller particles which he called ATOMA (greek for indivisible)

3 HISTORY OF THE ATOM ATOMS John Dalton 1808
suggested that all matter was made up of tiny spheres that were able to bounce around with perfect elasticity and called them ATOMS

4 Dalton’s Atomic Theory (experiment based!)
All elements are composed of tiny indivisible particles called atoms Atoms of the same element are identical. Atoms of any one element are different from those of any other element. John Dalton (1766 – 1844) Atoms of different elements combine in simple whole-number ratios to form chemical compounds In chemical reactions, atoms are combined, separated, or rearranged – but never changed into atoms of another element.

5 Discovery of the Electron
In 1897, J.J. Thomson used a cathode ray tube to deduce the presence of a negatively charged particle: the electron

6 Modern Cathode Ray Tubes
Television Computer Monitor Cathode ray tubes pass electricity through a gas that is contained at a very low pressure.

7 HISTORY OF THE ATOM PLUM PUDDING MODEL 1904
J.J. Thompson develops the idea that an atom was made up of electrons scattered unevenly within an elastic sphere surrounded by a soup of positive charge to balance the electron's charge like plums surrounded by pudding. PLUM PUDDING MODEL

8 Robert A Millikan 1916 US Physicist carried out experiments to find the charge and mass of an electron. An electron carries exactly one unit of negative charge, and its mass is 1/1840 the mass of a proton. 1840 e to = 1 proton

9 Eugen Goldstein 1886 Goldstein used the cathode ray tube to observe the proton. A proton has a positive charge and is located in the nucleus of an atom.

10 James Chadwick 1932 English physicist that discovered the neutron.
The neutron does not have a charge and is located in the nucleus of an atom.

11 Ernest Rutherford 1910 Oversaw Geiger and Marsden carrying out his famous experiment. They fired Helium nuclei at gold foil which was only a few atoms thick and found that most of them passed through. He later said that atoms are mostly empty space.

12 8 Scientist Contribution
1. Democritus-believed that atoms were indivisible and indestructible and note that he did not use an experiment, he only hypothesized. 2. John Dalton came up with the Atomic Theory. The 4 points can be found on page 102. Also note that Dalton did use an experiment for his findings.

13 8 Scientist Contribution
3. J.J. Thompson discovered the electron. Thompson also proposed that an atom is very much like “Plums in Pudding model”. 4. Robert A. Millikan carried out experiments to find the charge and mass of an electron. An electron has the mass of 1/1840 the mass of a proton. 5. Eugene Goldstein discovered the proton. 6. James Chadwick discovered the neutron. 7. Ernest Rutherford discovered the nucleus of an atom. 8. Neils Bohr stated that electrons orbit the nucleus like the planets orbit the sun.

14 HISTORY OF THE ATOM gold foil helium nuclei helium nuclei Rutherford found that while most of the helium nuclei passed through the foil, a small number were deflected and, to their surprise, some helium nuclei bounced straight back.

15 Ernest Rutherford’s Gold Foil Experiment - 1911
Alpha particles are helium nuclei - The alpha particles were fired at a thin sheet of gold foil Particles that hit on the detecting screen (film) are recorded

16 HISTORY OF THE ATOM However, this was not the end of the story.
Rutherford’s new evidence allowed him to propose a more detailed model with a central nucleus. He suggested that the positive charge was all in a central nucleus. With this holding the electrons in place by electrical attraction However, this was not the end of the story.

17 HISTORY OF THE ATOM Niels Bohr 1913
studied under Rutherford at the Victoria University in Manchester. Bohr refined Rutherford's idea by adding that the electrons were in orbits. Rather like planets orbiting the sun. With each orbit only able to contain a set number of electrons.

18 Bohr’s Atom electrons in orbits nucleus

19 HELIUM ATOM + - + - Shell proton neutron electron
What do these particles consist of?

20 ATOMIC STRUCTURE Particle Charge Mass proton + 1 charge 1 neutron No charge 1 electron -1 charge 1/1840

21 Distinguishing Among Atoms Terms
Atomic Number Mass Number Isotopes Atomic mass unit amu Complete Calculating average atomic mass worksheet. Atomic mass Periodic table Period Group

22 number of electrons = number of protons
ATOMIC STRUCTURE He 2 Atomic number the number of protons in an atom 4 Atomic mass the number of protons and neutrons in an atom number of electrons = number of protons

23 Complete Symbols Contain the symbol of the element, the mass number and the atomic number. Mass number X Superscript → Atomic number Subscript →

24 ATOMIC STRUCTURE Electrons are arranged in Energy Levels or Shells around the nucleus of an atom. first shell a maximum of 2 electrons second shell a maximum of 8 electrons third shell a maximum of 8 electrons

25 1. Electronic Configuration
ATOMIC STRUCTURE There are two ways to represent the atomic structure of an element or compound; 1. Electronic Configuration 2. Dot & Cross Diagrams

26 N DOT & CROSS DIAGRAMS Nitrogen
With Dot & Cross diagrams elements and compounds are represented by Dots or Crosses to show electrons, and circles to show the shells. For example; X Nitrogen N 7 X X N X X 14 X X

27 DOT & CROSS DIAGRAMS O Cl
Draw the Dot & Cross diagrams for the following elements; X 8 17 X O Cl a) b) X 35 X 16 X X X X X Cl X X X X X X X O X X X X X X X X X X

28 P E N of Atoms Now we will learn how to find the P E N of any element.
What does P E N stands for? Now I will go to the board and teach PEN. Pause the Power point Mr. Casby.

29 Br Symbols 80 35 Find each of these: number of protons
number of neutrons number of electrons Atomic number Mass Number 80 Br 35

30 Symbols If an element has an atomic number of 34 and a mass number of 78, what is the: number of protons number of neutrons number of electrons complete symbol

31 P E N of Atoms Class get into 5 equal groups.
Group 1 will find the P E N of all the elements in Period 1, 2 and 3. Group 2 will find the P E N of all the elements in Period 4. Group 3 find the PEN for Period 5 elements. Group 4 find the PEN for Period 6 elements. Group 5 find the PEN for Period 7 elements.

32 We can also put the mass number after the name of the element:
Naming Isotopes We can also put the mass number after the name of the element: carbon-12 carbon-14 uranium-235

33 Isotopes are atoms of the same element having different masses, due to varying numbers of neutrons.
Protons Electrons Neutrons Nucleus Hydrogen–1 (protium) 1 Hydrogen-2 (deuterium) Hydrogen-3 (tritium) 2

34 Isotopes Now I will go to the board and teach Ni-60 and Ni-61. Pause Here Mr. Casby!!! There are 3 different kinds of neon atoms. But how do they differ? They all have the same number of protons, but a different number of neutrons, as shown on page 113. What are the 3 types of Hydrogen?

35 Atomic Mass How heavy is an atom of oxygen?
It depends, because there are different kinds of oxygen atoms. We are more concerned with the average atomic mass. This is based on the abundance (percentage) of each variety of that element in nature. We don’t use grams for this mass because the numbers would be too small.

36 Composition of the nucleus
Atomic Masses Atomic mass is the average of all the naturally occurring isotopes of that element. Isotope Symbol Composition of the nucleus % in nature Carbon-12 12C 6 protons 6 neutrons 98.89% Carbon-13 13C 7 neutrons 1.11% Carbon-14 14C 8 neutrons <0.01% Carbon =

37 Average Atomic Mass I will now teach you all how to calculate the average atomic mass. Form groups and find the average atomic mass of an atom that is assign by me. Complete the average atomic mass worksheet.

38 Avg. Atomic Mass Two isotopes of copper Cu-63 and Cu-65
72% copper x63= 28% copper x65=+18.20 Makes the average amu

39 Summary Remember the 7 scientist that contributed to the discovery of the atom. Who are they? Remember the 3 subatomic particles and their charge. How many electrons equal the mass of 1 proton. What goes in the nucleus of an atom?

40 Summary The Atomic number of an atom = the number of proton in the nucleus of an atom. Atomic mass equal protons plus neutrons. The number of protons = the number of electrons. Electron orbit the nucleus in the shell. Each shell can only hold a set number of electrons.

Download ppt "ATOMIC STRUCTURE."

Similar presentations

S.MORRIS 2006. HISTORY OF THE ATOM 460 BC Democritus develops the idea of atoms he pounded up materials in his pestle and mortar until he had reduced.

S.MORRIS HISTORY OF THE ATOM 460 BC Democritus develops the idea of atoms he pounded up materials in his pestle and mortar until he had reduced.
(greek for indivisible)

(greek for indivisible)
“Atomic Structure”. The Greek philosopher Democritus (460 B.C. – 370 B.C.) The Greek philosopher Democritus (460 B.C. – 370 B.C.) He believed that atoms.

“Atomic Structure”. The Greek philosopher Democritus (460 B.C. – 370 B.C.) The Greek philosopher Democritus (460 B.C. – 370 B.C.) He believed that atoms.
SECTIONS 18-1 and 18-2. HISTORY OF THE ATOM 460 BC Democritus develops the idea of atoms He pounded up materials in his pestle and mortar until he had.

SECTIONS 18-1 and HISTORY OF THE ATOM 460 BC Democritus develops the idea of atoms He pounded up materials in his pestle and mortar until he had.
Chapter 4 “Atomic Structure”

Chapter 4 “Atomic Structure”
S.MORRIS 2006. Papercuts This piece of paper is 28cm x 2.5 cm How many times would you have to cut this piece of paper to be the same width as an atom?

S.MORRIS Papercuts This piece of paper is 28cm x 2.5 cm How many times would you have to cut this piece of paper to be the same width as an atom?
The History of the ATOM.

The History of the ATOM.
MADANIA (High School) Grade 10 CHEMISTRY Handout 1 Atomic Structure (Atomic number and Mass number) 19 / 07 / 2010.

MADANIA (High School) Grade 10 CHEMISTRY Handout 1 Atomic Structure (Atomic number and Mass number) 19 / 07 / 2010.
S.MORRIS 2006. HISTORY OF THE ATOM 460 BC Democritus develops the idea of atoms he pounded up materials in his pestle and mortar until he had reduced.

S.MORRIS HISTORY OF THE ATOM 460 BC Democritus develops the idea of atoms he pounded up materials in his pestle and mortar until he had reduced.
S.MORRIS 2006. Where did it all begin? The word “atom” comes from the Greek word “atomos” which means indivisible. The idea that all matter is made up.

S.MORRIS Where did it all begin? The word “atom” comes from the Greek word “atomos” which means indivisible. The idea that all matter is made up.
1 salt crystals 6 helium (in a balloon) 2 FeSO 4.7H 2 O(s) 7 steel 3 aluminium foil 8 ice 4 HNO 3 (aq) 9 CH 3 COOH(l) 5 sodium carbonate solution 10 Br.

1 salt crystals 6 helium (in a balloon) 2 FeSO 4.7H 2 O(s) 7 steel 3 aluminium foil 8 ice 4 HNO 3 (aq) 9 CH 3 COOH(l) 5 sodium carbonate solution 10 Br.
ATOMIC STRUCTURE S.MORRIS 2006

ATOMIC STRUCTURE S.MORRIS 2006
HISTORY OF THE ATOM 460 BC Democritus develops the idea of atoms he pounded up materials in his pestle and mortar until he had reduced them to smaller.

HISTORY OF THE ATOM 460 BC Democritus develops the idea of atoms he pounded up materials in his pestle and mortar until he had reduced them to smaller.
What is Matter? n/cells/scale/http://learn.genetics.utah.edu/content/begi n/cells/scale/

What is Matter? n/cells/scale/ n/cells/scale/
HISTORY OF THE ATOM 460 BC Democritus develops the idea of atoms He got the idea that everything was made of small bits by looking at sand on the beach.

HISTORY OF THE ATOM 460 BC Democritus develops the idea of atoms He got the idea that everything was made of small bits by looking at sand on the beach.
HISTORY OF THE ATOM 460 BC Democritus develops the idea of atoms he pounded up materials in his pestle and mortar until he had reduced them to smaller.

HISTORY OF THE ATOM 460 BC Democritus develops the idea of atoms he pounded up materials in his pestle and mortar until he had reduced them to smaller.
S.MORRIS 2006. HISTORY OF THE ATOM 460 BC Democritus develops the idea of atoms he pounded up materials in his pestle and mortar until he had reduced.

S.MORRIS HISTORY OF THE ATOM 460 BC Democritus develops the idea of atoms he pounded up materials in his pestle and mortar until he had reduced.
HISTORY OF THE ATOM 460 BC Democritus develops the idea of atoms he pounded up materials in his pestle and mortar until he had reduced them to smaller.

HISTORY OF THE ATOM 460 BC Democritus develops the idea of atoms he pounded up materials in his pestle and mortar until he had reduced them to smaller.
Chapter 4 “Atomic Structure”. Section 4.1 Defining the Atom The Greek philosopher Democritus (460 B.C. – 370 B.C.) was among the first to suggest the.

Chapter 4 “Atomic Structure”. Section 4.1 Defining the Atom The Greek philosopher Democritus (460 B.C. – 370 B.C.) was among the first to suggest the.
Chapter 4 “Atomic Structure”. Section 4.1 Defining the Atom OBJECTIVES: OBJECTIVES: Describe Democritus’s ideas about atoms. Describe Democritus’s ideas.

Chapter 4 “Atomic Structure”. Section 4.1 Defining the Atom OBJECTIVES: OBJECTIVES: Describe Democritus’s ideas about atoms. Describe Democritus’s ideas.

Similar presentations

Ads by Google