Grade 11 CBC/CBE Chemistry: Counting Atoms, Molecules and Ions in 2 Steps |

One glass of water holds more water molecules than there are glasses of water in all the oceans. How can anyone count them? In this Grade 11 CBC/CBE Chemistry lesson you will learn to count particles just by weighing. You will use the mole as the central station between mass and particles, find the number of molecules and atoms in a sample, count the ions in an ionic compound such as calcium chloride, and see why a polyatomic ion counts as one ion. You will also find the mass of a single atom, work backwards from a number of particles to a mass, and see why equal masses hold different numbers of particles. FREE REVISION PAPER FOR THIS LESSON Paper 1: Core concepts Download them here: https://drive.google.com/file/d/1TFB8... IN THIS LESSON 0:00 Hook and title 0:31 In this video 1:05 Moles are the central station 1:59 Example: molecules in 8.8 g of CO₂ 2:43 Matatus and passengers 3:24 Example: atoms in 8.8 g of CO₂ 4:12 Inside a spoon of salt 4:52 Counting the ions in CaCl₂ 5:37 Example: ions in 11.1 g of CaCl₂ 6:41 A polyatomic ion counts as one 7:24 Particles in one mole 8:16 The mass of one particle 8:57 Example: the mass of one iron atom 9:41 From particles back to mass 10:24 Your turn: oxygen atoms 11:11 Your turn: ions in calcium nitrate 12:12 Your turn: work backwards 12:43 Working backwards, step by step 13:46 Find the mistake: ions in salt 14:31 Find the mistake: ions in Na₂SO₄ 15:01 Equal masses, equal numbers? 15:41 Watch out for these mistakes 16:39 Going further: how big is a water molecule? 17:28 What to remember 18:10 Challenge and next video YOUR CHALLENGE A 500 cm³ bottle is full of water. The density of water is 1.0 g per cm³. How many water molecules does the bottle hold? (H = 1, O = 16, L = 6.0 × 10²³) Write your answer in the comments. PREVIOUS LESSON Lesson 4: Mass to moles and back :    • Grade 11 CBC/CBE Chemistry: Mass to Moles ...   NEXT LESSON Lesson 6: Percentage composition. What percentage of a fertiliser's mass is nitrogen, and how do you work it out? ABOUT SP-SciLearn SP-SciLearn makes paced, interactive science and math lessons for Kenyan learners following the CBC/CBE curriculum. Every lesson stops so that you can try a question yourself before the answer appears. Subscribe and turn on notifications so that you do not miss the next lesson. Grade 11 CBC/CBE Chemistry · 1.1 The Mole #Grade11Chemistry #CBEKenya #Chemistry