What is the entire universe made up of?

What is the entire universe

made up of?

The periodic table of elements

Fr Ra Ac Rf Db Sg Bh Hs Mt Ds Rg ? ? ? ? ? ? ?

Cs Ba La Hf Ta W Re Os Ir Pt Au Hg Tl Pb Bi Po At Rn

Rb Sr Y Zr Nb Mo Tc Ru Rh Pd Ag Cd In Sn Sb Te I Xe

K Ca Sc Ti V Cr Mn Fe Co Ni Cu Zn Ga Ge As Se Br Kr

Na Mg Al Si P S Cl Ar

Li Be B C N O F Ne

H He

How do we know?

John Dalton (1766–1844)

An English chemist who revived the ancient Greek’s idea of matter and proposed:

“All matter is made up of atoms. Atoms are the smallest particles of matter and cannot be broken down into smaller units”

Joseph Thomson (1856–1940)

A British physicist who discovered and experimented with cathode rays. It was found that these rays consisted of what are later called electrons by Thomson.

“An atom is a ball of positive charge with electrons dotted evenly through it like currants in a plum pudding. Overall, the atom is neutral”

The “Plum Pudding” Model

Ernest Rutherford (1871-1937)

This New Zealand physicist attempted to prove Thomson’s model of the atom was correct and designed an experiment. However…

The “Plum Pudding” Model

Only a few atoms thick Gold foil

Tiny, positive alpha particles

Screen

They expected the alpha particles to pass straight through the atom… but

about 1 in 8000 got deflected by a large angle (some even got knocked back) – HOW?

Rutherford’s Gold Foil Experiment

James Chadwick (1891-1974)

In 1932, he performed an experiment to discover the third type of sub-atomic particle that is not deflected by an electric or magnetic field – the “neutron”.

Atomic Structure today (or yesterday)

Protons and neutrons are called nucleons.Nucleus is very small compare to the size of the whole atom but has 99.95% of the mass.Electrons move around the nucleus in an unknown way.

Nucleus is made up of protons and neutrons which are bound together by nuclear force.