As per the rule, oxidation number of alkaline earth metals in their compounds is +2. Oxidation number of oxygen in it's compounds is -2(except peroxides) and the sum of oxidation numbers of all the elements of a neutral compound is zero.
"outside visible spectrum" would be the right way to define the power of the goggles provided to the soldiers to see at night. The correct option among all the options that are given in the question is the first option or option "A". I hope the answer comes to your great help.
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.
Answer:
The correct answer is - (Choice A) A Photosynthetic plants can move carbon from the atmosphere into an ecosystem’s food web.
Explanation:
Photosynthesis is the process performed by photosynthetic or green plants in presence of light atmospheric carbon dioxide and water converted into glucose (6 carbon compound) and oxygen.
This glucose or sugar is utilized by the plants that are producers in the ecosystem food web. These producers are fed by consumers and carbon molecules transfer from all the trophic levels in the food chain or food web in the process.
Answer:
Is soft
Explanation:
because concrete is hard ash so t hink flour would be safer