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Explore the fundamental concepts of the atomic structure, including the nucleus, protons, neutrons, and electrons. Learn about atomic number, isotopes, and the organization of the periodic table. Discover the relationship between mass, atomic mass, groups/families, and reactivity of elements. Differentiate between metals, metalloids, and nonmetals based on their properties. Test your knowledge with engaging assessments and gain a comprehensive understanding of the elements and their behaviors.
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Nucleus • Center of the atom. • Makes majority of the atom’s mass. • Made of Protons and Neutrons. Nucleus
Protons • Part of the nucleus • Have positive (+) charge
Neutrons • Part of the nucleus • Have neutral charge
Electrons • Orbit around the nucleus • Have negative (-) charge
Atomic Number • Definition: the number of protons in the nucleus • Tells us the identity of the element. Every element is defined by the number of protons in its nucleus
Isotopes • Atoms with the same number of protons but different numbers on neutrons • Example: Carbon So you can change the number of neutrons and the element still maintains its identity
Questions • 1) What particles make up an atom? • 2) What are the charges on these particles? • 3) What particles make up the nucleus?
Questions • 1) What is Oxygen’s atomic number? • 2) How many protons does Oxygen have? • 3) If I have 4 protons what element am I? • 4) If I have 4 neutrons what element am I?
Atomic Mass • Definition: the ~ mass of one atom of an element • Tells us how much one atom weighs in atomic mass units. Mass
Organization of The Periodic Table Group/Family Period Ordered by atomic mass. Columns arranged to form groups with similar properties
Assessment • Which element has the greatest atomic mass? • Lithium • Sodium • Potassium • Rubidium
Reactivity • The ease and speed with which an element combines, or reacts, with other elements or compounds Pure sodium reacts explosively with air
Groups/families of elements have similar reactivity Group 1: metals that react violently with water Group 18: Gases that barely react at all
Atoms have neutral charge • # of Protons (+) = # of Electrons (-) = 0 charge • Example: Hydrogen • How many electrons does C have?
Take home message • The properties of an element can be predicted from its location on the Periodic Table
Metals • Shiny • Solids (at room temp) • Malleable – can be hammered flat • Ductile – can be pulled into wire • High Conductivity – ability to transfer heat or electricity to another object
Reactivity of Metals Low High Metals will usually lose electrons when they react with other elements
Nonmetals • Opposite of properties of metals • Not shiny • Poor conductors • Mostly gases (at room temperature) • Solids are brittle Sulfur
Reactivity of Nonmetals Low Low High Nonmetals will usually gain or share electrons when they react with other elements
Some Important Nonmetals • Carbon – important element for making up living organisms • Noble Gases – group 18 – very nonreactive. Have full outer shells.
Metalloids • Inbetween metals and nonmetals • Solids (at room temp) • brittle and hard • Semiconductors – can conduct electricity under some conditions but not others. • very important for computer chips • Most common example – Silicon – in sand and glass
Assessment • The atomic number is the number of • valence electrons. • neutrons. • protons in the nucleus. • electrons in the nucleus.
Assessment • The periodic table is a chart of the elements that shows the repeating pattern of their • energies. • properties. • element symbols. • names.
Assessment • Which piece of information cannot be found in a square on the periodic table? • Atomic mass. • Chemical symbol. • Atomic number. • Number of neutrons.
Assessment • Which side of the periodic table contains most of the nonmetals? • Left side. • Right side. • Middle.
Assessment • Which is not a property of nonmetals? • Brittle. • Nonmalleable. • High conductivity. • Most are gases at room temperature