Answer:
The molecules have (a) volume and (b) attractive forces
Step-by-step explanation:
At ordinary conditions, the molecules are so far apart that the gases behave almost ideally.
However, if you use high pressure and/or low temperatures, you force the molecules to be close together.
There are <em>two competing effects</em>:
- The attractive forces become much stronger at close distances, so the volume is less than that predicted by the Ideal Gas Law.
- The volume of the molecules becomes a significant portion of the volume of the container. The molecules have less volume in which to can move around, so the pressure is higher than that predicted by the Ideal Gas Law.
In 1869 he published a table of the elements organized by increasing atomic mass.
Mendeleev is called the "father of the modern periodic table
stated that if the atomic weight of an element caused it to be placed in the wrong group, then the weight must be wrong. (He corrected the atomic masses of Be, In, and U)
was so confident in his table that he used it to predict the physical properties of three elements that were yet unknown.
After the discovery of these unknown elements between 1874 and 1885, and the fact that Mendeleev's predictions for Sc, Ga, and Ge were amazingly close to the actual values, his table was generally accepted.
However, in spite of Mendeleev's great achievement, problems arose when new elements were discovered and more accurate atomic weights determined.
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Answer:
D.
It produces H* in solution.
Answer:
Explanation: Nickel is element number 28 on the period table with a mass number 58 or 60, it exist in two forms and the phenomenon is known as isotopy
Definition of Isotopy is simply a phenomenon whereby elements exist in various forms that have the exact same chemical properties but different atomic mass.
58-Ni has atomic number 28 because that's the number o the element on the periodic table. Proton number is the same as atomic number and same as electron number for a neutral element or element without charge.
Mass number = Proton number (P) + Neutron number (N)
58 = 28 + N
N= 58-28
N= 30
58-Ni has 28 has the atomic number, proton number and electron number because it is a neutral atom but the neutron is 30 as shown in the calculation above.
60-NI+2 has a contrasting figure because the element has a charge of +2
Mass number= Proton + Neutron
60 = 28 + N
N= 60 - 28
N= 32
Electron = Proton - Charge
28 - (+2)
28 - 2
Electron = 26
The number of electron in 60-Ni +2 differs from 58-Ni because of the number of charge
Electron number differs from proton number in any element with a charge.
Answer: - 5.00 kJ
Explanation:
1) The heat evolved during the reation is proportional to the number of moles dissolved.
2) Proportionality = ratio is constant
<span>3) δh°soln of HNO3 is –33.3 kJ/mol => ratio 1
-33.3 kJ
ratio 1 = ---------------------
1 mol HNO3
4) ratio 2
x
--------------
0.150 mol
</span>
5) proportion
ratio 1 = ratio 2
x -33.3 kJ
--------------- = -------------- => x = 0.150 mol * (-33.3kJ) / 1 mol = - 4.995 kJ ≈
0.150 mol 1 mol
≈ - 5.00 kJ
