Which list of elements contains two metalloids?(1) Si, Ge, Po, Pb (3) Si, P, S, Cl(2) As, Bi, Br, Kr (4) Po, Sb, I, Xe
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The answer is (1). Si and Ge are both metalloids (semimetals)
Given are the steps in the titration process:
- Clean and rinse the burette with water
- Read and record the initial burette volume.
- Fill the burette with standardized base solution
- Rinse the burette with standardized base solution
The steps in the titration process is as follows:
1.) Clean and rinse the burette with water
2.) Rinse the burette with standardized base solution
3.) Fill the burette with standardized base solution
4.) Read and record the initial burette volume
Ans) 1.3 bison/mile
Soln:} See according to the question, Yellowstone National Park has an average of about 4500 bison living in it.
Area covered by Yellowstone park is 3472 miles.
So, to find the density of bisons living in Yellowstone Park we have to divide the no. of bisons by given area.
= 4500/3472
which is approximately 1.3 bisons per mile.
Therefore option a) is correct
Hope it helps!!!
Lead is a basic metal and almost 11 isotopes of Lead are reported. The isotopes with greater natural abundance are as follow;
1) ²⁰⁸Pb with abundance 52.4 %
2) ²⁰⁶Pb with abundance 24.1 %
3) ²⁰⁷Pb with abundance 22.1 %
4) ²⁰⁴Pb with abundance 1.4 %
Molar mass of ²⁰⁸Pb:
Molar mass of any element is the total of number of protons, neutrons and electrons.
As, number of protons in Lead are 82 then in ²⁰⁸Pb isotope number of neutrons are...
# of Neutrons = M.mass - # of protons
# of Neutrons = 208 - 82
# of Neutrons = 126
Result:
Molecular Mass of Lead (²⁰⁸Pb) is 208 amu.
# of Protons in ²⁰⁸Pb = 82
# of Neutrons in ²⁰⁸Pb = 126
The first one is remove heat
Second is add heat
