aim 1.....how did the atomic model  evolved over time?

aim 2.....what are the subatomic particles?

aim 3.....what is the wave-mechanical model?

aim 4.....what are the valence electrons?

aim 5.....what are isotopes?

honors

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cross-word puzzle

skills students should be able to do

• relate experimental evidence  to models of the atom

• use models to describe the structure of an atom

• calculate the mass of an atom, the number of neutrons or the number of protons, given the other two values 

• determine the number of protons or electrons in an atom or ion when given one of these values

• draw a Lewis electron-dot structure of an atom 

• distinguish between valence and non-valence electrons, given an electron configuration, e.g., 2-8-2 

• given an atomic mass, determine the most abundant isotope 

• calculate the atomic mass of an element, given the masses and ratios of naturally occurring isotopes

• distinguish between ground state and excited state electron configurations, e.g., 2-8-2 vs. 2- 7-3

• identify an element by comparing its bright-line spectrum to given spectra

real-world connections

• flame tests

• neon lights

• fireworks

• forensic analysis

• spectral analysis of stars

• lasers

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Words: atom, average, chemical, electron, emitted, energy, excited, identify, isotopes, mass, modern, neutron, number, opposite, orbitals, positively, subatomic, valence, wave- mechanical

The _______ model of the atom has evolved over a long period of time through the work of many scientists. Each _____ has a nucleus, with an overall positive charge, surrounded by one or more negatively charged electrons. __________ particles contained in the nucleus include protons and neutrons. The proton is _________ charged, and the neutron has no charge. The _________ is negatively charged. Protons and electrons have equal but _________ charges. The _________ of protons equals the number of electrons in an atom. The _____ of each proton and each neutron is approximately equal to one atomic mass unit. An electron is much less massive than a proton or a _________. In the _________________ model (electron cloud model), the electrons are in ________, which are defined as the regions of the most probable electron location (ground state). Each electron in an atom has its own distinct amount of _______.  When an electron, in an atom, gains a specific amount of energy, the electron is at a higher energy state (_______ state). When an electron returns from a higher energy state to a lower energy state, a specific amount of energy is _______. This emitted energy can be used to _________ an element. The outermost electrons in an atom are called the _________ electrons. In general, the number of valence electrons affects the __________ properties of an element. Atoms of an element that contain the same number of protons but a different number of neutrons are called ________ of that element. The average atomic mass of an element is the weighted _________ of the masses of its naturally occurring isotopes.

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