The mass of N-15 is 15 amu.
Chemical elements are represented using their symbols, their mass number and their proton numbers. The mass number of this isotope of nitrogen is shown next to the symbol. Regardless of the mass of the isotopes, their proton number is the same, which is 7.
40 electrons
Explanation:
The N for silicon tetrachloride, SiCl₄ is 40 electrons. The needed electrons that would be used to complete the lewis structure of the compound is actually 40 electrons. This number of electron will help the compound attain a noble configuration.
- The compound SiCl₄ is a covalent one. Here, there is sharing of electrons between two atoms.
- In drawing the electron dot formula, one must take into account the Available electrons and the Needed electrons.
- The Available electrons are sum of the valence electrons that can be accessed for the bonding. Si has 4 valence electrons, Cl has 7 valence electrons this makes a total of 4 + 7(4 atoms of chlorine), 32 available electrons.
- But to make a complete octet like that of noble gases, each atom most have 8 complete outer most electrons. This is the needed number of electrons. Since there are 5 atoms i.e 4 atoms of chlorine and 1 atom of Silicon, the needed electrons will be 5x8 = 40 electrons.
Learn more:
lewis structure : brainly.com/question/6215269
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The choices can be found elsewhere and as follows:
a. mass-mass problems
<span>b. mass-volume problems </span>
<span>c. mass-particle problems </span>
<span>d. volume-volume problems
</span>
I believe the correct answer is option D. It is volume-volume problems that does not require the use of molar mass. <span> Here you are dealing with molarities and volumes to determine concentrations. Molar mass is not part of any calculations.</span>
The number of atoms in a molecule can be calculated by adding all of the number of elements from the chemical formula. For chlorophyll, the chemical formula would be <span>C55H72MgN4O5 adding all the elements we have 137 atoms. Hope this answers the question.</span>
