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:
The correct alternative is "Option a".
Explanation:
Oxidation has become a mechanism whereby the physicochemical properties transform attributed to the formation of O₂.
- The connection involving magnesium as well as O₂ requires the oxidation of the component named magnesium.
- Even before exposed to the air, silicon is oxidized as well as generates silicon dioxide.
Other possibilities are not connected to the scenario in question. So Choice A is the best option.
Answer:
Kinetic energy increases.
Explanation:
In a solid, molecules do not have much room to move. They are very slow moving, which means that kinetic energy is low. In a liquid, molecules have more room to move. They are able to move faster than a solid, which means that kinetic energy is low.
From greatest to lowest kinetic energy:
gas, liquid, solid
Answer:
1. Lysine
2. Aspartic acid
3. Serine
4. Alanine
5. Tryptophan
Explanation:
Amino acids are biomolecules that contain two functional groups and one R side chain. The two functional groups are: carboxyl group and amino group.
The α-amino acids are the amino acids in which the two functional groups and the R side chain are attached to the α-carbon of the amino acid. They are total 22 α-amino acids.
1. A basic amino acid: Lysine is a positively charged, polar basic amino acid with a lysyl side chain.
2. An acidic amino acid: Aspartic acid is a negatively charged, polar acidic amino acid with an acidic carboxymethyl group.
3. A neutral polar amino acid: Serine is a polar and neutral amino acid with a hydroxymethyl group.
4. A non-polar aliphatic amino acid: Alanine is an aliphatic, nonpolar and neutral amino acid with a methyl side chain.
5. An aromatic amino acid: Tryptophan is an aromatic, nonpolar and neutral amino acid with an indole side chain.
