Around Atomic Structure Misconceptions Around Atomic Structure

Do students “get it?” Most are puzzled about the whole thing. Many see it merely as impenetrable mathematics with no relevance to reality. Some can do the algorithmic “plug-and-chug” calculations without too much difficulty. A few have a satisfactory conceptual understanding. A couple are inspired by it and want to learn more.

Students’ Misconceptions about Particles Some students equate atoms with molecules Discussion Particulate nature of Gases Some students think sodium chloride is a molecule How to approach teaching this concept ?? (You could use the ionic bonding worksheet to determine students’ present understanding and then discuss and build on a sounder basics.)

Students’ Misconceptions about Atoms True or False Atoms are like miniature solar systems

Students’ Misconceptions about Atoms The only thing an atom and the solar system have in common, is both are mostly empty space.

Students’ Misconceptions about Electrons True or False Electrons are little spheres that orbit the nucleus of an atom

Students’ Misconceptions about Electrons Electrons have no known shape and almost no mass. They do not orbit; they move randomly in an electron cloud.

The model above represents the most modern version of the atom. Is this really an Atom? Many of the models that you have seen may look like the one below. It shows the parts and structure of the atom. Even though we do not know what an atom looks like, scientific models must be based on evidence. The model above represents the most modern version of the atom.

Do students “get it?” The difficulty for us as teachers is using models to explain abstract concepts

What should a Model look like? Scientific models may not always look like the actual object. This is a painting of a young woman by Pablo Picasso. Does it actually look like a young woman?

What should a Model look like? A model is an attempt to use familiar ideas to describe unfamiliar things in a visual way. The model should also allow you to explain the properties https://www.youtube.co m/watch?v=IlkY- HtjrkA

Discussion with Students Explain that this is an animation of what chemists perceive as the probable positions of the electron in the atom Discussion with students based on quantum numbers Energy of the Electron Shape of Orbital Direction of Orbital Spin of Electron Recall that four quantum numbers are described the orbital and the electron in the orbital Energy Level, Shape, Direction - orbital Spin - electron

The Wave Model Today’s atomic model is based on the principles of wave mechanics. According to the theory of wave mechanics, electrons do not move about an atom in a definite path, like the planets around the sun. Electrons whirl about the nucleus billions of times in one second

The Wave Model In fact, it is impossible to determine the exact location of an electron. The probable location of an electron is based on how much energy the electron has. According to the modern atomic model, an atom has a small positively charged nucleus surrounded by a large region in which there are enough electrons to make an atom neutral.

Electron Cloud: Depending on their energy they are locked into a certain area in the cloud. Electrons with the lowest energy are found in the energy level closest to the nucleus Electrons with the highest energy are found in the outermost energy levels, farther from the nucleus.

Important Waves can act as particles, and particles can act as waves. Like light, electrons also have properties of both waves and particles. The whole idea of the two-sided nature of waves and particles is referred to as the wave-particle duality of nature.

Students’ Misconceptions about Electrons True or False The electron is the same size as a proton or neutron

Students’ Misconceptions about Electrons The electron has very very small size with practically no mass compared to a proton or a neutron.

Very Important!!!!! When teaching we visualize electrons as clouds and their positions as probable positions. We need to avoid the illustration of atoms using Bohr models.

Perhaps Allow students to choose a particle and write an illustrated “biography.” Include the particle’s discovery, charge, and location in the atom. Discussion on their findings – To arrive the correct model of the atom

Indirect Evidence Indirect Evidence is evidence gathered without being able to directly observe the object. The Atomic - Molecular Theory of Matter is based upon a vast amount of indirect evidence gathered over a long period of time. Just like pieces being added to a puzzle, each new bit of information gives us a better understanding of atoms.