Archive for the ‘ Obj 1-Atoms ’ Category

Obj 1-General Atomic Structure & Formation Molecules from Atoms

Basic Info about Atoms

Matter = Volume x Mass

Atoms = Nucleus (Protons + Neutrons) + Electrons

Atomic No = no Protons = no Electrons

Nuclear No= no Protons + Neutrons

Volume of Atoms = Volume Electrons’  Shell

Mass of Atoms = Mass Protons + Neutrons

Isotopes = Atoms of same no Protons & Electrons but differ in No Neutrons

Molecule = 2 or more atoms linked by chem bond

Element = Similar atoms in one molecule

Compounds = Differents atoms in one molecule

Energy Level = electron state of potential energy

= evolve around nucleus

= determine atomic properties

= absorption energy cause electrons move to higher level

= can be transferred (carrying energy) > REDOX REACTIONS

Bonds = achieved stability when outermost energy level has 8 electrons

= by electrons’  loss & gain (ionic) / share (covalent)

= contain energy & require energy to form or be broken

=bond energy (as kcal/mole) = energy needed to break a bond

= H-H (436 )  /  C-H (414)  /  C-C (343)  /  C-O (351)

H , O , C , N make up 99+% of atoms in human body

= O (63%)   /   H (25.2%)   /   C (9.5%)   /   N (1.4%)

Q- What property unites H,O,C,N and renders these atoms so appropriate to the chemistry of life

A-Their ability to form covalent bonds by electron-pair sharing

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