Answer:
C. naturally uncombined with other elements.
Explanation: Calcium is a chemical element with the symbol Ca and atomic number 20. As an alkaline earth metal, calcium is a reactive metal that forms a dark oxide-nitride layer when exposed to air.
Answer:
![\boxed{\text{6.95 u; Li}}](https://tex.z-dn.net/?f=%5Cboxed%7B%5Ctext%7B6.95%20u%3B%20Li%7D%7D)
Explanation:
1. Atomic mass of T
To get the atomic mass of T, you calculate the weighted average of the atomic masses of the isotopes.
That is, you multiply the atomic mass of each isotope by a number representing its relative importance (e.g.., its percent of the total).
![\begin{array}{ccrcr}\textbf{Atom} & \textbf{Mass/u} &\textbf{Percent} & \textbf{Calculation}& \textbf{Result/u}\\^{6}\text{T}& 6.02 & 7.42 & 6.02 \times 0.0742 & 0.45\\^{7}\text{T}& 7.02 & 92.58 & 7.02 \times 0.9258& 6.50\\& & &\text{TOTAL } = &\textbf{6.95}\\\end{array}](https://tex.z-dn.net/?f=%5Cbegin%7Barray%7D%7Bccrcr%7D%5Ctextbf%7BAtom%7D%20%26%20%5Ctextbf%7BMass%2Fu%7D%20%26%5Ctextbf%7BPercent%7D%20%26%20%5Ctextbf%7BCalculation%7D%26%20%5Ctextbf%7BResult%2Fu%7D%5C%5C%5E%7B6%7D%5Ctext%7BT%7D%26%206.02%20%26%207.42%20%26%206.02%20%5Ctimes%200.0742%20%26%200.45%5C%5C%5E%7B7%7D%5Ctext%7BT%7D%26%207.02%20%26%2092.58%20%26%207.02%20%5Ctimes%200.9258%26%206.50%5C%5C%26%20%26%20%26%5Ctext%7BTOTAL%20%7D%20%3D%20%26%5Ctextbf%7B6.95%7D%5C%5C%5Cend%7Barray%7D)
2. Identity of T
Lithium has an atomic mass of 6.64 u.
Element T is lithium.
Answer:
Explanation:
N-n : 167 (energy) 145 (length)
N=n : 418 (energy) 125(length)
N (three lines)n : 942 (energy) (110) length
(not sure if I’m too late but I asked my teacher and she looked at the answer sheet so it’s correct )