N UCLEAR F USION



How does the Sun work?

A TOMIC S TRUCTURE Our Model of the Atom

N UCLEAR F USION

 How does the Sun work?

 Can we do fusion like the sun?

 Why does fusion make sense?

 Why doesn’t fusion make sense?

W HY CAN ’ T WE DO THAT ?

U NDERSTANDINGS

  Atoms contain a positively charged dense nucleus composed of protons and neutrons (nucleons) Negatively charged electrons occupy the space outside the nucleus  The mass spectrometer is used to determine the relative atomic mass of an element from its isotopic composition Skills   Use nuclear symbol notation to deduce p, n, e Calculations involving atomic masses and abundance of isotopes from given data

S UBATOMIC PARTICLES

B ASIC V OCAB

 Mass Number A – number of protons + neutrons  Atomic Number Z – number of protons; fundamental characteristic of an element  Atomic Mass – The weighted average mass(according to relative abundances) of all the naturally occurring isotopes of an element compared with an atom of the carbon isotope which has a mass of exactly 12.

B ASIC V OCAB

 Isotope – Two or more atoms of the same element with different numbers of neutrons (and therefore different relative isotopic masses)  How is Mass Number different than Relative Atomic Mass (relative atomic mass)?

Symbol Atomic Number Protons Neutrons Electrons Mass Number

2.1.6 P ROPERTIES OF I SOTOPES

 Chemical Properties – remain the same  Physical Properties – change  Thus they can be separated and counted

ISOTOPE

H 2 0 D 2 O T 2 O H 2 17 O H 2 18 O D 2 18 O HDO HTO

PROPERTIES (BP 0 C)

100.0

101.4

101.5

100.1

100.2

101.5

100.7

100.8

R ADIOISOTOPES

 Read article online and do the assignment.

http://www.world-nuclear.org/info/inf55.html

Q UESTIONS

1. The nucleus of an element contains 35 protons and 46 neutrons.

a) Identify the element b) c) Give the symbols for 2 different species consistent with this information, and state the number of electrons in each species.

A different atom of the same element contains 44 neutrons in its nucleus. Give the chemical symbol for this element and include its mass number (A) and the atomic number (Z).

M ORE QUESTIONS

2. Strontium-90, 90 Sr, is formed in nuclear reactors during the explosion of nuclear weapons. It is a radioactive isotope and generates beta particles as it decays. The half-life of strontium-90 is 29 years. If ingested it can cause leukemia and other cancers in humans. Find strontium on a periodic table, and then suggest a reason why some of the strontium-90 that is absorbed tends to remain in the body for a long time.

R EVIEW AT H OME

  IB Youtube Lessons http://www.youtube.com/richthornley Go to this site and watch the youtube videos that pertain to the assessment statements covered in class today.

V IDEO H ELP

At home please review the following

   Crash Course Chemistry https://www.youtube.com/watch?v=FSyAehMdpy I&list=PL8dPuuaLjXtPHzzYuWy6fYEaX9mQQ8 oGr&index=1 https://www.youtube.com/watch?v=QiiyvzZBKT8   Ben’s Chemistry Videos https://www.youtube.com/watch?v=v_Q2D8dq5H Q&list=PLJ9LZQTiBOFFDw QjstExbB0P5E9v_Zuh&index=5