Saturday, August 21, 2010

Group 5 Atoms

Sub-Atomic Particles

>Protons
The proton is a subatomic particle with an electric charge of +1 elementary charge. It is found in the nucleus of each atom, along with neutrons, but is also stable by itself and has a second identity as the hydrogen ion, H+
>Neutrons
The neutron is a subatomic particle with no net electric charge and a mass slightly larger than that of a proton.
>Electrons
The electron is a subatomic particle carrying a negative electric charge. It has no known components or substructure, and therefore is believed to be an elementary particle.
(after dicussung the subatomic particles proceed to Atomic Mass & Atomic #, AZPEN)

Atomic Mass
-                  equal to the sum of the number of protons and neutrons found in the nucleus
 Atomic Number
-                  based on the number of protons and neutron found in the nucleus
-                  Z=protons
Summary of AZPEN:
-                  Atomic Mass= neutrons+protons
-                  Z (Atomic Number)= protons=electrons
-                  Protons = atomic mass- neutrons
      = Atomic Number
-                  Electrons=protons
-                  Neutrons= Atomic mass-Atomic Number

-What are Ions? How do they gain charges? (Provide Illustrations)
An ion is an atom or molecule in which the total number of electrons is not equal to the total number of protons, giving it a net positive or negative electrical charge.
An anion, is an ion with more electrons than protons, giving it a net negative charge (since electrons are negatively charged and protons are positively charged).
Conversely, a cation is an ion with more protons than electrons, giving it a positive charge.
Since the charge on a proton is equal in magnitude to the charge on an electron, the net charge on an ion is equal to the number of protons in the ion minus the number of electrons.

-What are Isotopes? (Give examples & Illustrations)
Isotopes are different types of atoms (nuclides) of the same chemical element, each having a different number of neutrons. In a corresponding manner, isotopes differ in mass number (or number of nucleons) but never in atomic number. The number of protons (the atomic number) is the same because that is what characterizes a chemical element. For example, carbon-12, carbon-13 and carbon-14 are three isotopes of the element carbon with mass numbers 12, 13 and 14, respectively. The atomic number of carbon is 6, so the neutron numbers in these isotopes of carbon are therefore 12−6 = 6, 13−6 = 7, and 14–6 = 8, respectively.

Friday, August 20, 2010

Group 2, MEASUREMENTS

members:
Campanilla
Cinco
Concepcion
Cruz,Gabrielli
Cruz, Jayrene


MEASUREMENT
- defined as a process of comparing an object's physical quantities using a standard measuring device.
- involves numbers accompanied by the appropriate unit of measurement.

UNITS
- identify the physical quantity being measured.

CALLIBRATIONS
- lines and numbers found on measuring instruments
- represent certain place values

ACCURACY
-place value usually represented by the smallest lines on the measuring device
-smallest place value that can be read from the device

ACCURACY AND PRESCISION

ACCURACY
- how close the measurement is to the true value

PRECISION
- how close the measurements are to each other