course material

1. COLLAPSE 1. An atoms is the smallest component of an element,
containing neutron
COLLAPSE1. An atoms is the smallest component of an element, containing neutrons,
protons and electrons, and makes up everything around us. An element is a substance in
which all of the atom have the same atomic number. It is also defined as a substance which
cannot be broken down by chemical means.2. We learn what the world was like before we
had our current understanding. People used to think the world was flat, and that the stars
and sun revolved around earth. Overtime each bit of our current understanding of science
came gradually.3. Atomic number and mass number while the mass number is the sum of
the protons and neutrons in an atom, the atomic number is only the number of protons. The
atomic number is the value found associated with an element on the periodic table because
it is the key to the element’s indentity.4.Together, the number of protons and the number of
neutrons determine an elements’s mass number. Isotopes are variants of a particular
chemical element in which differ in neutron number although all isotopes of a given
element have the same number of protons.5. Electronegativity trends moves from left to
right elctronegativity increaseS. From top to bottom it decreases. Ionization energy for the
representative elements decrease goind down a group and increase going across a period
frorm left to right. Metallic character representative elemts increase going down a group
and decreases going from left to right across a period. Atomic size increases going down a
group but decreases going from left to right