The answer is C.
The vast difference in electronegativity of the oxygen and hydrogen in water, the O-H bond is polar.
Answer:
- <em><u>Mendeleev produced the first orderly arrangement of known elements.</u></em>
- <em><u>Mendeleev used patterns to predict undiscovered elements.</u></em>
Explanation:
- <u>Mendeleev produced the first orderly arrangement of known elements and used patterns to predict the undiscovered elements.</u>
Those two statments are true.
For the time being there were some 62 known elements. Before Medeleev some schemes to order part of the elements were proposed, but Medeleev showed the relationship between the atomic mass and the properties of the elements (supports second choice). This arrangement is known as the periodic table.
More importantly, Mendeleev predicted correctly the existance and properties of unknown elements, which is his major contribution: he left blanket spaces which where gradually filled when new elements where discovered (this supports the fourth choice).
The first modern chemistry book was written by Antoine Lavoisier (this discards first option).
Mendeleev ordered the elements by increasing mass number (this discards third choice), which was corrected later by the scientist Henry Moseley, who ordered the elements by increasing atomic number (number of protons).
Isotopes were not known by Mendeleev times, so this discards the last option.
Answer:
540.54 mmHg
Explanation:
We know that the partial pressure of a substance is defined as; Mole fraction * total pressure.
If the total amount of gases in the atmosphere is 100%, the mole fraction of nitrogen gas is now
78/100 = 0.78
Thus, partial pressure of nitrogen gas = 0.78 * 693 = 540.54 mmHg
Answer:
Diamond.
Explanation:
Having thermal conductivity of more than 2,000 WMK
WMK = Watts per Meter per Kelvin
