Answer:
1.The electonic configuration of elements and their position in the periodic table are related to each other, From the electronic configuration of the elements, we can determine the period and the group to which the element belongs
Let's consider, sodium with atomic number 11 and k, l, and M shells have 2,8,and 1 electrons. since, there are 3 principal energy levels so we concluded sodium belongs to third period M Shell(valance shell) has only 1 electrons. so sodium belongs to group 1.
2. Entire D-block elements are known as Transition Elements.
3. Group 17 is the halogen group.
4. Main group of elements are...... 1,2, and 13 through 18.
5. Group 18 are the noble gas elements .
12. a). Smaller
b). Increases
c). More reactive
d). Softer
7. a). k › Ca › Ge › Br › Kr
b). Ra › Ba › Sr › Ca › Mg › Be
9. a). Ca(calcium) ion is smaller.
b). Cl(chlorine) atom is smaller.
c). Mg(magnesium) atom is smaller.
10. a). F(fluorine)
b). Sr(strontium)
c). Pb(lead)
d). At(Astatine)
Answer:
78% nitrogen
Explanation:
It has been long agreed upon that our atmosphere is highly abundant with nitrogen. Our atmosphere is composed of 78% nitrogen and then other gases follow such as 21% oxygen, 0.9% argon, and 0.03% carbon dioxide with very small percentages of other elements.
1.59 moles
112211111111111112
