Question

1. elements in the first group have one outer shell electron and are extremely reactive. they are called ____________. 7. elements in the second group have 2 outer shell electrons and are also very reactive. they are called __________. 8. elements in groups 3 through 12 have many useful properties and are called __________. 9. elements in group 17 are known as \salt formers\. they are called __________. 10. elements in group 18 are very unreactive. they are said to be \inert\. we call these the __________. 11. the elements at the bottom of the table were pulled out to keep the table from becoming too long. the first period at the bottom called the __________. 12. the second period at the bottom of the table is called the __________. 13. the atomic number of scandium is __________. 14. the group number in which zinc is located is __________. 15. what is the period in which bromine is located? __________. 16. what is the atomic mass of neon? __________. 17. what is the chemical symbol for arsenic? __________. 18. how many protons, neutrons, and electrons are found in rubidium? p __________ n __________ e ____________

Explanation:

1. Elements in the first - group of the periodic table are alkali metals. They have one outer - shell electron and are highly reactive.
2. Elements in the second group are alkaline earth metals, with two outer - shell electrons and high reactivity.
3. Elements in groups 3 - 12 are transition metals, known for their useful properties like conductivity and malleability.
4. Group 17 elements are halogens, which readily form salts.
5. Group 18 elements are noble gases, which are inert due to their full outer - shell electron configuration.
6. The first period at the bottom of the periodic table is the lanthanide series.
7. The second period at the bottom is the actinide series.
8. Scandium has an atomic number of 21, which is the number of protons in its nucleus.
9. Zinc is in group 12 of the periodic table.
10. Bromine is in period 4 of the periodic table.
11. The atomic mass of Neon is approximately 20.18.
12. The chemical symbol for Arsenic is As.
13. Rubidium has an atomic number of 37 (number of protons and electrons), and its most common isotope has 48 neutrons.

Answer:

1. Alkali metals
2. Alkaline earth metals
3. Transition metals
4. Halogens
5. Noble gases
6. Lanthanide series
7. Actinide series
8. 21
9. 12
10. 4
11. Approximately 20.18
12. As
13. P: 37, N: 48, E: 37