Inside Atoms 7.1 Student Notes PDF

7.1 INSIDE ATOMS  Objectives Describe the structure of an atom. Define and use analogies. LET’S HAVE FUN!  Let’s Experiment (Group work ) In order to try to gain an idea of how small an atom really is, you will complete the following activity. 1. Cut the paper in half. 2....

7.1 INSIDE ATOMS  Objectives Describe the structure of an atom. Define and use analogies. LET’S HAVE FUN!  Let’s Experiment (Group work ) In order to try to gain an idea of how small an atom really is, you will complete the following activity. 1. Cut the paper in half. 2. Discard one half. 3. Cut the remaining piece in half. 4. Continue cutting and discarding the strips as many times as you can.  Results How many cuts were you able to make? Do you think you could keep cutting the paper forever? Why or why not? Atoms The Building Blocks of Matter: Atoms - - - ++ + - + + + - + + - - - Atoms Sodium is made of tiny particles called sodium atoms Diamond is made of carbon atoms different form sodium atom.  An Analogy is comparison between one thing and another, that helps to explain something. Analogies are useful in science.They help to explain things that are very small ,or very big. A model is an idea that explains observations and helps in making predictions. Solid sphere model  The first model used to describe the atom is : The solid atom model is good enough to explain the different properties of a substance in the solid liquid ,and gas states. (change in state) The model cannot used to explain or predict chemical reactions.  Class work “With your partner, Solve question 1 from the workbook p.47.”  Atoms Smallest possible unit into which matter can be divided, while still maintaining its - properties. Made up of: + – protons + + - - – neutrons + + – electrons The solar system is commonly - used as an analogy to describe - the structure of an atom. The force that holds the protons and electrons together is called electrostatic force  Subatomic particles Subatomic Relative The location Relative particle charge mass Proton 1+ The nucleus 1 Neutron 0 The nucleus 1 Electron 1- Surrounding It is very small the nucleus in its mass shell almost zero ( electron cloud ) 1/2000  Explain Why the nucleus contains most of the mass of the atom ? Because it is made up of protons and neutrons since they are much heavier than electrons.  Thinking and working scientifically The football stadium and pea is used as analogy to compare the size of the nucleus to the size of the atom. How ? If an atom was the size of a football stadium, the nucleolus would be the size of a pea. That explains how the nucleus is tiny compared to the atom.  What is the charge of the nucleus ? Why ? Positive since it has protons and neutron protons have positive charge and neutrons are neutral.  What is the charge of an atom ? Atoms are neutral because they contain the same number of electrons which are negatively charged ,and protons which are positively charged. Number of protons = Number of electrons  Class work “With your partner, solve Question 2 And 3 from the workbook p. 47”.  What holds an atom together ? An individual atom is held together by the electrostatic attraction between its positively charged nucleus and its negatively charged electrons.