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Chemistry of Life. Matter is anything that has mass and volume . . All matter is composed of individual building blocks called atoms . . Atoms are composed of 3 particles, protons , neutrons , and electrons . . Protons have positive ( + ) charge. Neutrons have no charge (neutral).
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Chemistry of Life Matter is anything that has mass and volume. All matter is composed of individual building blocks called atoms. Atoms are composed of 3 particles, protons, neutrons, and electrons.
Protons have positive (+) charge Neutrons have no charge (neutral) Electrons have negative (-) charge
Protons and Neutrons are bunched together in the atomic nucleus. Electrons move around the nucleus in Energy levels, which represent their most probable location at any one time.
Lewis Diagrams, or “Energy Levels Simplified” Lewis Diagrams portray electron Energy levels as circles around the nucleus H
The number of protons in an atoms nucleus is equal to the atoms atomic number. Ex: Chlorine has Atomic Number 17, and has 17 protons in the nucleus carbon has Atomic Number 6, and has 6 protons in its nucleus.
Carbon 6P 6N Atomic Number 6
Neon 10P 10N Atomic Number 10
In a free atom (one with no charge), the number of electrons is equal to the number of protons. The number of neutrons is usually equal to the number of protons.
Neon 10P 10N Atomic Number 10
Oxygen 8P 8N Atomic Number 8
A substance made of only 1 kind of atom is called an element. Ex: Gold, Copper, Aluminum, Helium, Neon, Oxygen
An atom that has a different number of neutrons is called an isotope. The number of protons and electrons remains the same. Since neutrons have no charge, the charge on the atom is the same.
Carbon 14 6P 8N Atomic Number 6
Octet/Duet Rule:atoms combine in such a way that their outer energy levels are completely filled by electrons. 1st energy level: 2 electrons 2nd and 3rd levels: 8 electrons Remember: “2-8-8”
1P 2P HYDROGEN HELIUM
Atoms that combine and SHARE electrons form a COVALENT BOND Similar atoms that form covalent bonds produce MOLECULES Ex: H2, O2
1P 1P HYDROGEN HYDROGEN The Hydrogen atoms will combine in such a way as to share the outer electrons.
1P 1P HYDROGEN MOLECULE By sharing the electrons, each atom “sees” both, and is satisfied. A molecule of hydrogen results. (H2)
Atoms that transfer electrons from one to another form IONIC BONDS. Different atoms that combine to form ionic bonds produce IONIC COMPOUNDS Ex: Sodium Chloride (NaCl), a.k.a. “table salt”
11P 17P v v Charge: 0 Charge: 0 Chlorine atom Sodium atom 2 Free Atoms, but both want to react Why?
17P v 11P v Charge : -1 Charge: +1 Chloride ion Sodium ion
Because ions are now oppositely charged, they attract each other. The bond formed by ions is called an ionic bond. Na+ and Cl- ions form a lattice like structure with alternating ions.
Blue =Chlorine Green = Sodium