- Law of Definite Proportion

- Established a law stating that different samples of any pure compound contain the same proportions by mass.

- Father of Chemical Theory

- He proposed a theory of the particulate nature of matter.

- Law of Multiple Proportion

DALTON’S ATOMIC THEORIES

1. Matter is made up of extremely small divisible particles called atom.

DALTON'S ATOMIC THEORIES

2. Atoms of the same element are identical and are different from those of other elements.

DALTON'S ATOMIC THEORIES

3. Compounds are formed when atoms of different elements combine in certain whole-number ratios.

DALTON'S ATOMIC THEORIES

Atoms rearrange only during a chemical reaction to form new compound. Atoms are not created nor destroyed.

Discovered the electron, a negatively charged particle in the atom. And described the atom as a plum pudding model.

The two philosophers concluded the smallest unit particle and named this “atomos”.

- Suggested that atoms of elements combine to form different compounds.

- He also defined element as the simplest composition of matter that cannot be broken down further by any chemical means.

- Founder of Chemistry

He studied more on the concepts of elements and compounds. He isolated gas which he called “dephlogisticated air” by heating mercury oxide.

Proposed the different types of atoms have different weights and that all atoms have the same speed regardless of size.

Discovered the electron, a negatively charged particle in the atom. And described the atom as a plum pudding model.

He was an early investigator of discharge tubes, the discoverer of anode rays, and is credited with the discovery of the proton.

He was awarded the 1935 Nobel Prize in Physics for his discovery of the neutron in 1932.

Determined the electric charge carried by a single electron using the oil drop experiment.

- Gold Foil alpha scattering experiment

- Investigated the alpha and beta rays and used the alpha particles to discovered a very dense, positive charged nucleus surrounded primarily by empty space.

He theorized that electrons had several possible orbits at different distance from the nucleus.

He demonstrated that the major properties of an element are determined by the atomic number, not by the atomic weight by correlating the frequencies of the x-rays to a series of whole numbers that assigned to each element.

First to demonstrated the electrical nature of matter.

He proposed that x-rays coming from within the potassium uranyl sulfate exposed the film introducing the rays to magnetic field.

- Discovered the radioactivity that explained the rays deflected when exposed to magnetic field.

- First to received a Nobel prize in Physics

He discovered penetrating rays that could travel through walls emitted from a vacuum discharged tube.

Discovered the rays similar to x-ray emitted from radioactive materials but even more penetrating and have neither mass nor charge. 

Elements are made up of only two types of atoms.

Two different atoms = compound

Took pioneering steps in developing atomic theory and also made a series of symbols for atoms and molecules. He also carried out research into colorblindness (from which he himself suffered).

Changed these symbols into letter symbols

He noticed that certain elements in groups of 3 had similar physical and chemical properties with the atomic weight of the middle element being halfway between the other two.

- Law of Octaves

- He arranged the elements in order of increasing atomic weight

- Every 8th known element had similar physical and chemical properties.

Created a spiral periodic table.

- He established the periodicity of elements based on their physical properties.

- He arranged it by increasing atomic mass and based on the valency of the elements.

1869 - He drew up the first periodic table of the known elements of his time by arranging the elements in order of increasing atomic masses.

- He used the physical properties of elements to establish a pattern.

- He also separated metal from non-metals.

1913 - Arranged the elements in order of increasing atomic number

1-7

1-18 columns

1-8 set a and set b

s, p, d, f

1st and 2nd column or IUPAC

3rd and 12th column or IUPAC

13th and 18th column or IUPAC

57th (lanthanoids) and 71st and 89-103 (actinoids) elements

SET A (includes s-block and p-block)

SET B(d-block)

f-block

alkali metals

alkaline earth metals +1

early transition metals +2

late transition metals

Boron group/earth metals +3

carbon group -4

nitrogen group/pnictrogens -3

Chologens group/oxygen group -2

Halogens group (salt formers)

noble gases (inactive) (most stable elements)

defined as 1/2 distance between neighboring nucleus in molecule or crystal

- amount of energy required to remove valence electron from an atom in gaseous atom to form cation, indicates how strongly an atom holds onto its outermost electrons,

- amount of energy required to remove valence electron from an atom in gaseous atom to form cation, indicates how strongly an atom holds onto its outermost electrons,

- amount of energy released or absorbed when an electron is added to gaseous atoms, forming anion. Noble gases energy is absorbed, others are release. Measurement of the atom's tendency to form negative ion, electronegativity: ability of atom to attract electrons toward itself.

electrically charged particles that exist in very high temperature

have definite volume but no definite shape and follows the shape of the container

Exist in nearly absolute zero and make the particles to be fused together and become identical

With definite shape and volume wherein particles cannot be compressed.

low density and has a great expansion during heating

Iron slowly corrodes when exposed to a moist environment to form reddish-brown rust.

The water is clear, colorless odorless with a density of 1 g/ml and a boiling point of 100 degrees Celcius.

Characteristics that can be observed without changing the substance into another substance.

Characteristics that can be observed when a substance undergoes a change in its composition.

The type of change that occurs when the composition of the substance is not altered in the process.

The type of change indicated by any change in color, odor, taste or release of gas.

It involves the splitting and combining of subatomic particles in the central part of atom.

Isotopes are atoms of the same element but different mass due to the number of protons.

According to atomic theory, atoms of the same elements are identical and the same with other elements.