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You are watching: What element has 3 valence electrons

The price is Cl.

Group/family 18, the Nobel Gases, have complete octets the 8 valence electrons. Each time you relocate to the LEFT one time in ~ the nonmetals ~ above the routine Table, an electron is lost. So, any kind of element in group/family 17 would have actually 7 valence electron (you deserve to check...

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The answer is Cl.

Group/family 18, the Nobel Gases, have complete octets that 8 valence electrons. Every time you relocate to the LEFT one time in ~ the nonmetals ~ above the routine Table, an electron is lost. So, any kind of element in group/family 17 would have actually 7 valence electrons (you can check this by illustration Bohr diagrams for each facet within group/family 17).

So, we now know that the facet is a nonmetal found in group/family 17. Therefore, that is found in the "p" block. For elements found in the "p" block, durations represent power levels. 

Thus, if I match the third period with group/family 17, ns have uncovered my answer- Chlorine! 

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usage the periodic Table come answer such questions. The valence electrons space those in the outermost power level and are often used in bonding. Each family members (or group or column) ~ above the PT have a specific variety of valence electrons. For example Group 1, the alkali metals, (Li, Na, K, etc.) have actually 1 valence electron. Team 2, the alkaline earth metals, (Be, Mg, Ca, etc.) have 2 valence electrons. Groups 3-12, the shift metals, have 2 valence electron (most of them) but some have d electron that might be affiliated in bonding too. Group 13 elements have 3 valence electrons. Group 14 facets have 4 valence electrons. Group 15 facets have 5 valence electrons. Group 16 elements have 6 valence electrons. Group 17 elements have 7 valence electrons. Team 18 elements have 8 valence electrons. 

So from the description, you can conclude the the facet described, with 7 valence electrons, have to be in team 17. 

Next you need to decipher what the three power levels indicates. The electrons fill up the energy levels in the electron cloud indigenous the shortest level first. Once that power level is filled, the electrons begin to to fill the next highest energy level. Interestingly, the regular table is collection up together that aspects in the an initial row (Period 1) have actually their valence electron in the very first energy level. Duration 2 facets have your valence electron in the second energy level, etc.

So from the description, the element has three power levels. It"s valence electrons must be in the 3rd energy level, and also therefore the element must be in period 3 top top the regular Table. 

Thus the aspect described need to be in period 3, team 17, which is Chlorine, price Cl.

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This is a really broad science question regarding elements. Based upon the details that was detailed one can narrow down the pool of elements to a particular family or team of elements.

The 3 orbitals is important information but it is general since most facets that have actually over 11 electrons will have a 3rd orbital. The significant bit that information noted was the valence electrons. Valence electron tells united state that it has seven electrons in that is outermost orbital. V that in mind, we deserve to narrow the facet down to the Halogens or group 17.

In regards to which particular element, the clue that the valence electrons room in the 3rd orbital narrows it to Chlorine. The remaining aspects would not have actually seven valence electrons in the 3rd orbital.

What is the the symbol of the element that has three power levels and seven valence electrons?

This can be conveniently done using your routine table. The rows of a regular table indicate the number of energy level an element has. Therefore to discover an aspect with three power levels you want to go to the 3rd row down. Currently to uncover the facet with 7 valence electron you deserve to use the columns (aka groups) an element is in. The an initial column means those aspects have 1 valence electron, the second column way those elements have 2 valence electrons, and so on. The just tricky component is you need to skip the transition metals (the middle group). The tendency picks increase again on pillar 13, those facets have 3 valence electrons, team 14 has 4 valence electrons, team 15 has actually 5 valence electrons, group 16 has actually 6 valence electrons, and group 17 has actually 7 valence electrons. So us are looking for the aspect in the third row and also 17th group or column and there us will uncover Chlorine, symbol Cl.

her question requires electron configurations, valence electrons, and the routine table, all in one. There space multiple means to deal with this question, all arriving at the exact same answer. I"m not sure which renders the many sense come you, yet here that goes:

1. The Aufbau principle (long way)

For this question, friend no doubt have currently referenced and learned the Aufbau principle because that electrons, the order at which electrons fill the various power levels and also sublevels roughly a nucleus. While well-known the bespeak is best, don"t be fear to watch it increase in your textbook. You"ll discover a variety of means describing it, but you should see the diagonal dominion attached to this price which travel guide you with them. You need to know around the various sublevels (s,p,d, and also f) and also the variety of electrons each can hold (2, 6, 10, and 14). Once looking in ~ the coefficients of each letter, you"re actually seeing the different energy levels that the sublevels belong to. For your question, you want the element that has three energy levels and also 7 valence electrons, or 7 electron on the third energy level. If girlfriend trace through the image, the first sublevel friend hit on the third energy level is the 3s, which have the right to only hold 2 electrons. Due to the fact that you want 7 valence electrons, you need to account because that the various other 5. If you save tracing the image, you then pertained to the 3p sublevel, which have the right to hold 6, but you only have actually 5 left. This way that the last component of her configuration should be 3p^5. Follow to the Aufbau principle, each energy level (and sublevel) should be filled before you fill the next. In other words, everything prior to 3p have to be full. Map along the diagonal rule and you come at:

1s^2 2s^2 2p^6 3s^2 3p^5

Each superscript (exponent) speak you how plenty of electrons room in every sublevel. If you include them all up, you have actually 17. Thus, this aspect that has actually three power levels and 7 valence electron must have actually 17 electrons total. As soon as you look at the periodic table, chlorine, Cl, is atomic number 17.

2. The Aufbau Principle and the routine Table (the easier way)

The more electron configuration you occupational out and also study, the more comfortable girlfriend will become with them. The odd shape of the periodic table stems native the setup of all the electrons about a nucleus for each element. Attached, you"ll find one more image because that the Aufbau principle, except it overlaps the regular table. To make feeling of it, start in the height left in ~ hydrogen, and then map your finger to the best (helium). Then walk to heat two, starting at where lithium is found and also again trace right until you find neon. If you proceed in this pattern, you are complying with the bespeak of the sublevels. Your question asks because that an element with three power levels and also 7 valence electrons. If you map the regular table, the an initial time you uncover something ~ above the 3rd energy level is 3s (the 3rd row). If you trace that row, you"ll relocate one spot over and also fill the 3s sublevel. You would have covered 2 facets for the 2 electron an s have the right to hold. 5 much more valence electrons need to be accounted for. If you proceed tracing that row, counting follow me the way, you"ll discover yourself in the p-block. If you count to five in the p-block, you"ll avoid in the place that chlorine can be uncovered on a standard regular table. It is the 7th element on row three of the periodic table, fifth element in p-block on heat three. Your answer is again chlorine, Cl.

3. The periodic table and groups (easiest way)

The team numbers ~ above the routine table reference electron configurations. Aspects in group 17 or group VIIA (same group), they will have actually 7 valence electrons. The heat or period an element is discovered on referrals the highest possible occupied energy level for the element. Because that an element to have actually three occupied power levels and 7 valence electrons, it need to be on heat three and in team 17 or group VIIA. Again, you uncover chlorine, Cl.

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They each arrive in ~ the very same answer. The only distinction is which means your brain likes to watch the issue.