Conservation Of Mass and Energy -

Matter can’t be
created or destroyed

... but can be

converted into energy

according to the formula ...

Mass (kg) to Energy (J)

Equation

E	=	m	c²
Units (J)		(Kg)	m/s

Nuclear Fireball

http://www.wpclipart.com/

c - speed of light = 3.00 x 10⁸m/s

Fission - splitting of a large nuclei into 2 or nuclei

http://www.wpclipart.com/

Ex) How much energy would you get if you converted 2.0 Kg to energy?

E	=	m	c²
Units (J)		(Kg)	m/s

E = 2.0 Kg(3.00 x 10⁸m/s)²

E = 1.8 x 10¹⁷ Joules

Finding the energy that can be obtained from the conversion of 1 proton (1 universal mass unit)

mass of a proton = 1.67 x 10^-27 Kg

(p. 1 reference)

Plug into equation

E = mc²

E = (1.67 X 10^-27 Kg)(3 x 10⁸m/s)²

= 1.5 x 10^-10Joules

Convert to eV:

1 eV = 1.6 x 10 ^-19Joules

E =	1.5 x 10^-10J
	1.6 x 10 ^-19 J/eV

= 9.31 x 10² Mev

or 931 MeV **

Our Sun

http://www.wpclipart.com/

To convert universal mass units to energy in MeV

1 proton

(universal mass unit)

converts

to 9.31 x 10²Mev
or 931 MeV

(p. 1 Reference)

(Mass/Energy Relationship)

Typical Regents Question ...

Ex) How much energy can be generated when 2 universal mass units are completely converted into energy?

1 universal mass unit = 931 MeV

Answer: 1862 MeV
(each universal mass unit
converted produces 931 MeV)

Forces inside nucleus

1) Strong nuclear force
(A.K.A. 'strong force')

• holds nucleus together - very strong, short range

• operates at distance < 10^-13 m

http://www.cassiopeiaproject.com/

| Onsite |

Fusion - Uniting of small nuclei
to form a larger nucleil

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Our sun is large fusion 'bomb'.

http://www.wpclipart.com/

The Elements: Forged in Stars

NOVA

Elements__Forged_in_Stars.mov

Author - "Fusion, which occurs when atomic nuclei combine to form new elements, is extremely powerful. All the stars in the universe, including the Sun, are nuclear furnaces fueled by fusion. Through fusion, stars are responsible for forming all the naturally occurring elements heavier than hydrogen and helium -- before stellar nucleosynthesis, only the lightest elements existed in the universe. This video segment adapted from NOVA illustrates the critical role that stars play in creating the elements."

A) Binding Energy - amount of energy needed to separate nucleons (protons and neutrons) in nucleus.

Protons and neutrons in nucleus in large nuclei have slightly less mass than n and p in small nuclei

Mass of Assembled
Nucleus

Combined mass of an
equivalent # of nucleons.

Lost mass
called mass defect

Mass Defect
=
Binding energy

(mass lost is
converted to energy)

Ex) If the mass defect is .1 universal mass units then the binding energy = ....

(p. 1 Reference)

1 Universal mass unit

converts to

9.31 x 10² Mev

(p. 1 ref)

9.31 x 10¹ Mev

This movie is part of the collection: Prelinger Archives

Producer: Sutherland (John) Productions
Sponsor: General Electric Company
Audio/Visual: Sd, C
Keywords: Atomic-nuclear: Energy; Physics; Animation

Creative Commons license: Public Domain

Subatomic
Particles

Enrichment

Finely_Tuned_Universe.mov

http://www.creationofuniverse.com