This table shows the pattern in the periodic table that Mendeleev developed and how the missing elements at that time could be predicted. Selenium: Value given for hexagonal, gray form. C. Period 2 , group 18. A. Na B. Si C. Cl D. Ar 20. ALKALINE METALS. Relative atomic mass of a light element up to calcium is approximately.....its atomic number. 4. Boron is an element that is in period 2 on the periodic table and has an atomic mass of 10.81 View Answer. Find your group chat here >> start new discussion reply. Period 2 , group 17. Ask your questions now >> Applying to uni? The highest principal quantum number of period 2 element is 2. Add the mass of protons and neutrons to compute the atomic mass of a single atom of an element. Classify each statement as true or false: 1. C. oxidation number D. mass number 19. Period 4 elements have an inner electron configuration of [Ar] 3. Navigate by clicking the element on the table above or using the table below. This list contains the 118 elements of chemistry. A.) Phosphorus: Value given for yellow phosphorus form. The second ionization energy will have to remove an electron located on a lower energy level. Carbon: Value given for diamond form. Its valence shell contains 2 electrons; They have low electronegativity Page 1 of 1. Electrons orbit the atom's nucleus in energy levels. False; 3.) True; B.) Period 3 , group 17. Watch. Based on the periodic trends for ionization energy, which element has the highest ionization energy? For rubidium, which is located in period 5, the second ionization energy will remove an electron from the fourth energy level. As the elements of Period 2 are considered in succession from left to right, there is a general decrease in A. ionization energy B. electronegativity C. metallic character D. nonmetallic character 21. 4.) Fluorine (F) Nitrogen (N) Helium (He) 2.) 5. Group 2 elements are called alkaline metals because they form alkaline solutions, hydroxides, when reacting with water and their oxides are found in the earthâs crust. This is because the increase in electrons is paralleled by an increase in shells. The atomic mass is useful in chemistry when it is paired with the mole concept: the atomic mass of an element, measured in amu, is the same as the mass in grams of one mole of an element. Thus, since the atomic mass of iron is 55.847 amu, one mole of iron atoms would weigh 55.847 grams. Period 5 elements have an inner electron configuration of [Xe] 6. D. Period 2 , group 1. Which element in Period 3 has the greatest tendency to gain electrons? Trend 2. Group 8A elements have completely full outer principal shells. From the periodic table you can see that carbon has an atomic number of 6, which is its proton number. View Answer. Group 1 metals are less reactive than group 2 metals. For potassium, which is located in period 4, the second ionization energy will remove an electron from the third energy level. The valence electrons of groups 5A elements are in the 6s subshell. B. Element in period 2 with the highest ionisation energy? They have low electron affinity. View Answer. Chemical elements listed by atomic mass The elemenents of the periodic table sorted by atomic mass. 2. 1. click on any element's name for further information on chemical properties, environmental data or health effects.. Nitrogen has a larger atomic radius than oxygen. Answer. Berkelium: Value given for alpha form. Announcements Join Uni of Surrey for a live Q and A on personal statements, 5pm on Thursday! Which has more metallic character, Lead (Pb) or Tin (Sn)? Sulfur: Value given for monoclinic, beta form. Another trend is the increase in the radius of elements as we move down a column, while the number of valence electrons remains the same, even though the atomic number keeps increasing. Notes on the Melting Point of particular elements: Helium: Helium does not solidify at standard pressure. Example: Find the atomic mass of a carbon isotope which has 7 neutrons.