Answer:
1. The first model.
2. The second model.
Step-by-step explanation:
In a Bohr Model, you have your nucleus in the middle, in #1, it's the relatively large black circle, and in #2, it is the large grey dot with the number of protons & neutrons in the center. Now the first ring of a Bohr Model can hold a maximum of 2 electrons. The second ring of a Bohr Model can hold a maximum of 8 electrons. If the element has more than 10 electrons, there will be a third ring (as is shown on your worksheet), and the third ring can hold a whopping 18 electrons!
Using that background, let's begin!
In question #1, looking at the first model shown, there are 2 electrons on the first ring, 3 electrons on the second ring, and 4 electrons on the third ring. The issue with this is that you must max out the number of electrons on a ring before moving to the next. If the model were to be correct, there would be 2 electrons on the first ring, and 7 electrons on the second - no third ring needed! The second model checks out in #1, as there are 2 on the first ring, and 7 on the second.
In question #2, the first model shows 2 electrons on the first ring, 8 electrons on the second ring, and 2 electrons on the third ring. This checks out! The second model in question #2 is showing 2 electrons on the first ring, and a whopping 11 electrons on the second ring - that's no good! If the model were to be correct, there would be 2 electrons on the first ring, 8 electrons on the second ring, and 1 electron on the third ring.