How did chemists change Mendeleev's periodic table in the early 1900s?

Chemistry

1 answer:

gavmur [86]3 years ago

6 0

Answer:

They used atomic number instead of atomic mass to organize the elements. From an element's location in the periodic table, you can predict: ... The elements have similar properties.

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Why does Beryllium have a larger first Ionization energy than boron?

Nata [24]

This is an exception to the general electronegativity trend. It can be explained by looking at the electron configurations of both elements.

Be:[He]2s2
B:[He]2s22p1

When you remove an electron from beryllium, you are taking away an electron from the 2s orbital. When you remove an electron from boron, you are taking an electron from the 2p orbital. The 2p electrons have more energy than the 2s, so it is easier to remove them as they can more strongly resist the effective nuclear charge of the nucleus.

7 0

4 years ago

What is the hydrogen ion concentration in a solution with a pH of 8.0??

finlep [7]

- log [H+] = 8
log [H+] = -8
10^(log [H+]) = 10^-8
[H+] = 1x10^-8 M

5 0

4 years ago

Identify the term that matches each electrochemistry definition.

anygoal [31]

Answer: a. Cathode

b. Galvanic cell

c. Anode

d. Electrolytic cell

e. half reaction

Explanation:

Galvanic cell or Electrochemical cell is defined as a device which is used for the conversion of the chemical energy produced in a spontaneous redox reaction into the electrical energy.

Electrolytic cell is a device where electrical energy is used to drive a non spontaneous chemical reaction.

In the electrochemical cell, the oxidation occurs at an anode which is a negative electrode and the reduction occurs at the cathode which is a positive electrode. Thus the electrons are produced at anode and travel towards cathode.

The balanced two-half reactions will be:

Oxidation half reaction : $M\rightarrow M^{n+}+ne^-$