Worksheets 2-6 KEYS

1 . Name Berkshi re Date Pd Honors Chemistry - Unit 5 Worksheet 2 Atomic Structure Properties of Subatomic Particles Symbol Relative Charge Particle Proton pt neutron no electron e +1 Relative Mass I amu I amu 1/1860 amu

2. The atomic number tells you the number of also tells you the number of Protons electrons ати in one atom of an element . It in a neutral atom of that element . The atomic . number gives the " identity " of an element as well as its location on the periodic table . No two different Same elements will have the 3. The mass number nucleus of the atom . atomic number . of an element is the total number of protons and neutrons in the 4. The mass number is used to calculate the number of neutrons in one atom of an element . from the In order to calculate the number of neutrons you must subtract the atomic # mass # 5. Give the symbol of and the number of protons in one atom of : Lithium Iron Li Fe 3 26 Oxygen 8 Krypton Kr 36 Br 35

Bromine Copper Cu 29 Mercury Ha 80 Helium He 2 Iodine I 53 Xenon Xe 54 6. Give the symbol of and the number of electrons in a neutral atom of : Uranium U B Boron 92 5 Chlorine Cl 17 7. Name the element which has the following numbers of particles :

a . 26 electrons , 26 protons b . 53 protons , 74 neutrons Iron lodine c . 2 electrons ( neutral atoms ) Helium d . 20 protons Calcium Hydroge n e . O neutrons 8. If you know ONLY the following information can you ALWAYS determine what the element is ? ( Yes / No ) a . Number of protons b . Number of neutrons c . Number of electrons in a neutral atom d . Number of electrons Fill in the missing items in the table below . Yes по yes no Complete the table . Use a periodic table where needed . There is enough information given for each element to determine all missing numbers . Symbol

Atomic Mass Number Number Number Number Number of of of Protons Electrons Neutrons 23 Na 1 1 23 1 1 1 1 12 40 19 K 19 40 19 19 21 90 Sr 38 38 38 38 52 19 9 . F 9