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frosja888 [35]
3 years ago
9

Which statements accurately describe Dmitri Mendeleev’s contributions to the development of the periodic table? Check all that a

pply.
Mendeleev wrote the first modern chemistry textbook.
Mendeleev produced the first orderly arrangement of known elements.
Mendeleev ordered the elements by increasing atomic number.
Mendeleev used patterns to predict undiscovered elements.
Mendeleev accounted for variations resulting from isotopes.
Chemistry
2 answers:
Varvara68 [4.7K]3 years ago
8 0

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.

Delvig [45]3 years ago
4 0

Answer:

The answer is B and D

Explanation:

I just took the test and got it right.

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Part A. Two containers, one at 305 K and the other at 295 K, are placed in contact with each other. 1. 1 J of heat flows from th
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Answer:

0.00011 JK.

The process does NOT violate the second law of thermodynamics

Explanation:

The following parameters are given which are going to help in solving for the change in entropy of the system. The term "entropy'' simply means the degree of disorderliness of a system.

=> The temperature of container A = 305 K, the temperature of container B = 295 K and the amount of heat generated when the containers are placed in contact with each other = 1. 1 J.

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The process does NOT violate the second law of thermodynamics.

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