chemistry C1 (1)

Periodic table

• here are about 100 different elements that are organised in the periodic table
• the metals are found on the left hand side of the table and the non-metals are found on the right
• the vertical columns in the table are called groups
• the horizontal rows are called periods

Atomic structure

• elements are the simplest chemical substance
• they are made of only on tyoe of atom and cannot be broken down into anything simpler by chemical methods
• an atom is the smallest part of an element that can take part in an chemical reaction
• atoms are made od s central nucleus which contains protons and neutrons
• around the nucleus there are orbiting electrons
• protons: 1 relative mass, + charge
• neutrons: 1 relative mass, no charge
• electrons: no mass, - charge
• atoms do not have a charge because they have the same number of protons and electrons which have equal and opposite electric charges

Periodic table structure

• the atomic number of the element is shown as the smaller number on the periodic table ans is the same as the number of protons in the nucleus
• this is sometimes called the proton number
• in the periodic table, elements are arranged in order of their atomic number
• each element also has a atomic mass which is the number of protons and neutrons in the nucleus
• no of neutrons = atomic mass- proton mass

Elements

• mercury and bromine are the two only elements liquid at room temperature

John Dalton's atomic theory

• john dalton was born in 1766
• he was amazingly clever- by the time he was 12 he was teaching other children
• dalton was intrested in almost anything, making observations of the wether as well as being the first person to study colour-blindness (he was colour-blind)
• dalton is best remembered of his odeas about chemistry ans in particular his theories about atoms

His theory

• all matter is made up of indivible particles called atoms
• atoms of the same element are similar in mass and shape but different from the atoms of other elements
• atoms cannot be created or destroyed
• atoms join together to form compound atoms (now called molecules) im simple ratios

• dalton's atomic…