ATOMIC STRUCTURE SUBATOMIC PARTICLES WHATS IN AN ATOM

ATOMIC STRUCTURE SUBATOMIC PARTICLES

WHATS IN AN ATOM? n THREE MAIN PARTICLES n PROTONS n NEUTRONS n ELECTRONS

WHERE ARE THEY? n IN CENTER: - PROTONS - NEUTRONS n ENERGY LEVELS SURROUNDING CENTER - ELECTRONS

WHAT’S THIS LOOK LIKE?

HOW DO MASSES COMPARE? MEASURED IN AMU’s. (this stands for atomic mass units) 1 AMU = the mass of 1 proton or 1 neutron Proton = 1 amu, or 1. 674 x 10 -24 grams Neutron = 1 amu or 1. 675 x 10 -24 grams Electrons = 0 amu or 9. 11 x 10 -28 grams Comparatively, electrons have 1/1836 the mass of either the proton or neutron

What are their electrical charges? n Proton + (positive 1) n Electron - (negative 1) n Neutron 0 (neutral)

Which particles are fundamental? n Electrons are fundamental (small as they go) n Protons and neutrons are NOT n These are composed of smaller particles called QUARKS n what are quarks?

HOW DO QUARKS WORK? n PROTONS = 2 UP QUARKS (+2/3, +2/3) 1 DOWN QUARK (-1/3) WHAT DOES THIS ADD UP TO? You guessed it! +1

How do quarks work? n Neutrons = 2 down quarks (-1/3, -1/3) 1 up quark (+ 2/3) What does this add up to? You guessed it! 0

WHAT FORCES ARE IN THE ATOM? n Remember “Fantastic Four”

4 Forces in the atom

ELECTROMAGNETIC FORCE n A force that combines the effects of electrical charge and magnetism. This force can either attract or repel the particles on which it acts. Oppositely charged particles attract each other, while like particles repel one another. Electrons are kept in the orbit around the nucleus by the electromagnetic force, because the nucleus in the center of the atom is positively charged and attracts the negatively charged electrons.

Electromagnetic Force • Likes-repel • Opposites-attract • This force keeps electrons In orbit • Acts upon the proton and Electron.

n STRONG NUCLEAR FORCE PROTONS PUSH AWAY FROM ONE ANOTHER BECAUSE OF THE REPELING ELECTROMAGNETIC FORCE. A NUCLEUS CONTAINING TWO OR MORE PROTONS WOULD FLY APART IF IT WERE NOT FOR THE STRONG FORCE. Like ”glue” the strong force keeps the protons together to form the nucleus. The strong forces and electromagnetic forces both hold the atom together

STRONG FORCE • Holds protons to the Neutrons in the nucleus • Overcomes the electromagnectic force • Acts on proton and neutron

GRAVITATIONAL FORCE n THIS FORCE ACTS ON ALL OBJECTS AT ALL TIMES. THE AMOUNT OF GRAVITY BETWEEN OBJECTS DEPENDS ON THEIR MASSES AND THE DISTANCE BETWEEN THE OBJECTS. GRAVITY FORCE IS VERY SMALL WITHIN ATOMS BECAUSE THE PARTICLES IN ATOMS ARE SO SMALL.

Gravitational Force n. Force that attracts the atom to the center of the earth. n. Very Small

WEAK FORCE n Weak forces are important because they are responsible for stabilizing particles through the process of radioactive decay, in which a neutron in the nucleus changes into a proton and an electron.

WEAK FORCE Causes radioactive decay n. Neutrons deteriorate (break down into proton and electron. ) n

PUT THE 4 FORCES IN CORRECT ORDER FROM STRONGEST to WEAKEST

Strong Electromagnetic Weak Gravitational