3.1 Atomic Structure And The Periodic Table

Front 1

State the relative charges and approximate relative masses of protons, neutrons and electrons

Back 1

Relative Charge :

Proton +1Neutron 0 Electron -1

Relative mass :

Proton 1Neutron 1 Electron 1/1836

Front 2

Define atomic number

Back 2

Define proton number (atomic number) as the number of protons in the nucleus of an atom

Front 3

Define mass number

Back 3

Define nucleon number (mass number) as the total number of protons and neutrons in the nucleus of an atom

Front 4

Use proton number and the simple structure of atoms to explain the basis of the Periodic Table, with special reference to the elements of proton number 1 to 20

Back 4

Each time you go across a period, lets say Helium, the atom has one more proton than the previous element.

~For Example, Hydrogen has one proton, and Helium has two.

~ Additionally, Lithium is now down a group so it has 3 protons.

~Moving along the period, you have Beryllium, Boron, Carbon, Nitrogen, Oxygen and so on.

~After we reach Ne (Neon) which has 10 electrons, we move on to the next group and a different energy level of electrons.

Front 5

Define isotopes

Back 5

They are atoms of the same element which have the same proton number but a different nucleon number http://www.bbc.co.uk/schools/gcsebitesize/science/aqa_pre_2011/radiation/radioactiverev1.shtml ~Understand that isotopes have the same properties because they have the same number of electrons in their outer shell

Front 6

Types and uses of isotopes

Back 6

~ two types as being radioactive and non-radioactive

~ Materials do not become radioactive if they absorb electromagnetic radiation such as x-rays and gamma rays. However, they can become radioactive if they absorb particles such as neutrons. This is put to good use in manufacturing medical radioisotopes.

~medical use : nuclear radiation is used in medicine to sterilise equipment, to help in diagnosis and to treat cancer with gamma rays.

~ Radioisotopes are used as tracers in industry. These are used for tracking substances. http://www.bbc.co.uk/schools/gcsebitesize/science/add_ocr_gateway/radiation/radioisotopesrev2.shtml

~carbon dating http://www.bbc.co.uk/schools/gcsebitesize/science/add_gateway_pre_2011/radiation/radioisotopesrev3.shtml

*https://youtu.be/nEL2H-xS_jA*http://www.bbc.co.uk/schools/gcsebitesize/science/aqa_pre_2011/radiation/radioactiverev1.shtml

Front 7

Describe build-up of electrons in ‘shells’

Back 7

Electrons are arranged in shells at different distances around the nucleus. As we move across each row of the Periodic Table the proton number increases by one for each element. This means the number of electrons also increases by one for each element.

~Starting from the simplest element, hydrogen, and moving through the elements in order we can see how the electrons fill the shells.

~The innermost shell (or lowest energy level) of electrons is filled first. This shell can contain a maximum of two electrons.

~Next, the second shell fills with electrons. This can hold a maximum of eight electrons. When this is filled, electrons go into the third shell, which also holds a maximum of eight electrons. Then the fourth shell begins to fill.

http://www.bbc.co.uk/schools/gcsebitesize/science/add_ocr_pre_2011/periodic_table/electronsrev1.shtml

Front 8

understand the significance of the noble gas electronic structures and of the outer shell electrons

Back 8

Electrons are arranged in shells. Each group is equivalent to one energy level and when you reach the end of the period of the group, you start off at a new group.~1st energy level holds up to 2 electrons

~2nd energy level holds up to 8 electrons

~3rd energy level holds up to 8 electrons

If an atom is in its 3rd energy level holding 8 electrons, the addition of 1 more electrons will push it to the 4th energy level.The atoms at the end of the periodic table have a full electron shell, so basically, no more additional electrons may be added on and it has no valence electrons. We call these Noble Gases.