Answer:
Explanation:
A marble is not a very large object, so a smaller graduated cylinder is a better choice. A 100 milliliter graduated cylinder is not needed to measure the volume of a small marble, so a 25 milliliter graduated cylinder is the best option.
All living organisms are composed of one or more cells. The cell is the basic unit of structure and organization in organisms. Cells arise from pre-existing cells.
I think it is A. produces the hydrogen ion
Answer:
HClO₃ /chloric acid /suffix -ic/ ClO₃⁻ (chlorate)
HClO₂/ chlorous acid/ suffix -ous/ ClO₂⁻ (chlorite)
HNO₃ /nitric acid /suffix -ic/ NO₃⁻ (nitrate)
HNO₂/ nitrous acid/ suffix -ous/ NO₂⁻ (nitrite)
Explanation:
Chlorine has 4 positive oxidation numbers to form oxyacids: +1, +3, +5 and +7.
- When it uses the oxidation number +5, it forms HClO₃, which is named chloric acid, with the suffix -ic. When it loses an H⁺, it forms the oxyanion ClO₃⁻ (chlorate).
- When it uses the oxidation number +3, it forms HClO₂, which is named chlorous acid, with the suffix -ous. When it loses an H⁺, it forms the oxyanion ClO₂⁻ (chlorite).
Nitrogen has 2 positive oxidation numbers to form oxyacids: +3 and +5.
- When it uses the oxidation number +5, it forms HNO₃, which is named nitric acid, with the suffix -ic. When it loses an H⁺, it forms the oxyanion NO₃⁻ (nitrate).
- When it uses the oxidation number +3, it forms HNO₂, which is named nitrous acid, with the suffix -ous. When it loses an H⁺, it forms the oxyanion NO₂⁻ (nitrite).
Answer:
- Nitrogen has four pairs of electrons: 3 bonds and 1 lone pair in the valence shell;
- Electrons repel one another based on the VSEPR theory;
- Nitrogen has a total of 7 protons (its atomic number is 7) in its nucleus.
Explanation:
The shape and the bond orientation of molecules and ions are both explained by the valences shell electron pair repulsion theory (VSEPR).
Ammonia, 
, is a molecule which contains three N-H bonds, as well as one lone pair on nitrogen. According to the VSEPR theory, molecules try to acquire a shape which would minimize the repulsion exhibited by the electron clouds present, that is, between the bonding (shared in a bond) and non-bonding (lone pair) electrons.
In VSEPR, our main step is to calculate the steric number, this is the sum of the number of bonds (ignoring the multiplicity of any bond) and the lone pairs on a central atom. In ammonia, we have 3 bonds and 1 lone pair, totaling to a steric number of 4. A steric number of 4 without any lone pairs on a central atom and just bonds would yield a tetrahedral shape with bond angles of 
.
Now, in this case, since we have a lone pair instead of a bond, it is repelling stronger decreasing the bond angles to about 
.
The greater the number of lone pairs, the lower the angle becomes.
To summarize:
- Nitrogen has four pairs of electrons: 3 bonds and 1 lone pair in the valence shell;
- Electrons repel one another based on the VSEPR theory;
- Nitrogen has a total of 7 protons (its atomic number is 7) in its nucleus.
