Fcat Study Guide Chemistry '10

1. Compare the reactions of sodium and potassium in water. 2. Why do you think that they reacted similarly?

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Click for Sodium and Potassium Movie

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The Periodic Table Groups or families are vertical columns in the periodic table The zig- zag line separates metals from non-metals

Group or

family Period

With the discovery of isotopes by Mosley in 1909, the Periodic Table was reorganized by increasing atomic number (number of protons).

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Atomic Number = # protons (+) Symbol

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Na 22.998

Energy Level filling 2 8 18 32

P+ N

Atomic Mass = Mass # (rounded)= protons + neutrons

Sodium contains how many of the following? Atomic # Mass #

Protons

Neutrons Electrons

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How many protons and electrons are found in an atom of Chlorine?

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How many neutrons are found in an atom of Sodium (Na) that has a mass number of 23 amu?

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What happens to an atom when you add another proton?

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How can you change the mass number of an atom of sodium?

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These are the electrons found in the last level of an atom.

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They are the MOST important electrons in determining the reactivity of an atom.

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Elements with the same number of valence electrons will react similarly. As a rule elements in the same group have the same number of valence electrons.

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For example: Hydrogen, Lithium, Sodium etc all have 1 valence electron. GROUPS 1A – 8A GIVE THE # OF VALENCE ELECTRONS

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Lithium is #3 in the periodic table. So it has THREE electrons. As we had stated before two electrons are in first level, leaving ONE electron in level 2. So Lithium has ONE valence electron.

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How many electrons are there in an atom of Sulfur (S)?

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How many valence electrons are found in an atom of Sulfur?

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Name an element that would have similar chemical properties to Sulfur. Click here for: Graphing Lab #2 Click here: Post Lab Clip

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Metals lose their valence electrons to form cations Cations = positive. (Cat’s whiskers) Click here for: Cation clip

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Nonmetals will gain enough electrons to form anions. They will take as many electrons they need to get 8 valence electrons. Anions = negative (An means to negate) Click here for: Anion clip

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Which chemical group…… 1. Reacts with water to form basic solutions 2. Readily combines in nature to form other compounds 3. Loses 2 outer energy level electrons to form +2 ions

Trahn’s card describes which group on the periodic table? F. Group 1 G. Group 2 H. Group 16 I. Group 18

FCAT Science Sample Test Book 2007 11 11

Julio is given an unknown element to study. After carefully analyzing his element he arrives at the following conclusions. His element has a very low density and when it reacts with other elements it gains 3 electrons to form an anion with a -3 charge.

In which of the following groups could we find Julio’s element? A) Group 3 B) Group 5 C) Group 13 D) Group 15

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3. Suppose a scientist makes an unexpected discovery about the possible existence of a new element. The finding does not fit well with the initial hypothesis. The scientist is a member of a team of researchers. If the team behaves according to the best principles of scientific inquiry, which of the following would NOT occur? A) rejection of the finding as being impossible. B) willingness to repeat the studies that led to the finding for confirmation. C) urging the scientist to communicate findings to other researchers. D) insistence on reviewing all data carefully and systematically for any errors.

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