Glaciers were found in Africa because continents were connected and party covered with snow near the south pole long ago.
The major limitation is that C) he can not definitively show what causes the difference.
It may be caused by <em>something the people are doing</em> (if so, what?) or it may be caused by <em>some environmental differences</em> or a<em> combination of both</em>.
Answer:
Explanation:
general expression for the ionization energy of any one-electron species.
= z² x ground level energy / n²
z is atomic no , n is energy level .
ground level energy of
H = 1.31 x 10³ kJ/mol
He⁺ = 2² x 1.31 x 10³ kJ/mol = 5.24 x 10³ kJ/mol
Li²⁺ = 3² x 1.31 x 10³ kJ/mol = 1.18 x 10⁴ kJ/mol
b ) the ionization energy of B⁴⁺.
= 5² x 1.31 x 10³ kJ/mol = 32.75 x 10³ kJ/mol
c ) minimum energy required to remove the electron from the n = 3 level of He⁺ per mole
= 5.24 x 10³ / 9 kJ/mol
= 5.82 x 10² kJ/mol
= 5.82 x 10² x 10³ / 6.02 x 10²³ J
.9667 X 10⁻¹⁸ J
= .9667 X 10⁻¹⁸ / 1.6 X 10⁻¹⁹ eV
= 6.042 eV
= 1237.5 / 6.042
= 204.82 nm
=
d )
According to the question, the determined melting point of the compound is 112.5-113.0oC. When the solidified compound was retried, the melting point was found to be 133.6-154.5oC. This greater range higher than 112°C is caused by reusing samples leads to errors.
A pure sample is known by its sharp melting point. A pure sample does not melt over a large range. We can see this in the predetermined melting points of the pure sample(112.5-113.0oC).
However, reusing a sample introduces errors because the pure sample may become contaminated leading to a larger and higher range of melting point (133.6-154.5oC) which is far above 112°C.
Learn more: brainly.com/question/5325004
The best way to determine the number of atoms of arsenic in the sample will be to multiply 2.3 by Avagadro's number.
This is because Avagadro's number is the number of particles one mole of any substance has, and its value is 6.02 x 10²³
If the number of moles of a substance are known, then multiplying by Avagadro's number will give the number of particles. In this case, this is 1.38 x 10²⁴.
