Answer the questions below for an element that has the electron configuration 1s2 2s2 2p6 3s2 3p3.
A. What is the symbol for this element?
B. What is the atomic number of this element?
C. How many unpaired electrons does an atom of this elelemt have?
D. How many valence electrons does an atom of this elelemt have?
E. How many inner shell electrons does an atom of this element have?
F. What is the highest occupied energy level for this element?
Count the electrons. I count 15 which is P. You can answer the others?
A- p
B- 15
E- three
F- 3p3
A. The symbol for this element can be determined by looking at the electron configuration. The last number in the electron configuration is the number of electrons in the highest energy level, which corresponds to the period or row on the periodic table. Therefore, this element is in the third period or row. The third period starts with sodium (Na) and ends with argon (Ar). The electron configuration given matches that of chlorine (Cl).
B. The atomic number of chlorine (Cl) is 17. Each element on the periodic table is assigned a unique atomic number which represents the number of protons in the nucleus of an atom.
C. The electron configuration provided indicates that there are 3 unpaired electrons in an atom of chlorine (Cl). Unpaired electrons are those that do not have another electron with opposite spin in the same orbital.
D. To determine the number of valence electrons for chlorine (Cl), we need to look at the outermost energy level. In this case, the third energy level (n=3) is the highest occupied energy level. The electrons in the 3s and 3p orbitals are considered to be valence electrons. In this electron configuration, there are 2 electrons in the 3s orbital and 3 electrons in the 3p orbitals, giving a total of 5 valence electrons.
E. To find the number of inner shell electrons, subtract the number of valence electrons from the total number of electrons in the atom. Chlorine (Cl) has a total of 17 electrons, as indicated by its atomic number. It also has 5 valence electrons, as determined in the previous step. Subtracting 5 from 17 gives 12. Therefore, chlorine has 12 inner shell electrons.
F. The highest occupied energy level for chlorine (Cl) is the third energy level (n=3). This can be determined from the electron configuration, where the highest energy level is the one in which electrons are filled last. In this case, the 3s and 3p orbitals are filled, indicating that the third energy level is the highest occupied level.
To answer these questions, let's break down the electron configuration step by step:
1. Electron Configuration: 1s2 2s2 2p6 3s2 3p3
A. The symbol for an element is determined by the number of protons in its nucleus. To find the symbol, we need to locate the element with an atomic number that matches the electron configuration. Looking at the electron configuration, we see that the highest energy level is 3, and there are 5 electrons in the 3rd energy level. This means that the atomic number of the element is 5. Referring to the periodic table, we find that the element with atomic number 5 is Boron (B).
B. The atomic number is the number of protons in an atom's nucleus. In this case, the atomic number is 5, which corresponds to Boron.
C. Unpaired electrons are those that occupy individual orbitals rather than being paired up with another electron in the same orbital. To determine the number of unpaired electrons, we look at the last orbital (3p) in the electron configuration. In this case, we see that there are 3 unpaired electrons in the 3p orbital.
D. Valence electrons are the electrons in the outermost energy level of an atom. To determine the number of valence electrons, we look at the highest energy level in the electron configuration. In this case, the highest energy level is 3, and there are 5 electrons in the 3rd energy level. However, the 3s and 3p orbitals are not considered valence orbitals since they are not in the highest energy level (they are 2 energy levels away from the nucleus). Therefore, Boron has 3 valence electrons.
E. Inner shell electrons are the electrons located in energy levels below the highest energy level. To determine the number of inner shell electrons, we need to subtract the number of valence electrons (which are in the highest energy level) from the total number of electrons in the atom. In this case, there are a total of 5 + 2 + 6 + 2 + 3 = 18 electrons. Since Boron has 3 valence electrons, it also has 18 - 3 = 15 inner shell electrons.
F. The highest occupied energy level is the energy level that contains the valence electrons. In this case, the highest energy level is 3, so the highest occupied energy level for Boron is 3.
To summarize:
A. The symbol for this element is Boron (B).
B. The atomic number of this element is 5.
C. An atom of this element has 3 unpaired electrons.
D. An atom of this element has 3 valence electrons.
E. An atom of this element has 15 inner shell electrons.
F. The highest occupied energy level for this element is 3.