# Tutor profile: Maya P.

## Questions

### Subject: Chemistry

Which element is the most electronegative? Explain.

Fluorine is the most electronegative atom. Electronegativity is the ability of an atom to attract a shared pair of electrons. On the periodic table, electronegativity increases as you move from left to right across the table. This is because the atomic number increases, meaning the atoms further to the right have more and more protons. Protons are found in the nucleus and attract electrons, holding them in orbit. Furthermore, electronegativity decreases as you move from top to bottom down the table. This is because as you go down a group, the elements have increasing numbers of electron shells, which makes it harder for the protons to hold in the electrons due to a large atomic radius. Therefore, since Fluorine is at the top right of the periodic table (apart from noble gases), it has the highest electronegativity. Noble gases are omitted because they already have a full outer shell of electrons and therefore do not want any more.

### Subject: ACT

Sample English Question: Which answer choice is the best version of this sentence: Having studied, my mother is a marine biologist. A. As my mother's interest is science, she is a marine biologist. B. My mother's occupation is that of a marine biologist. C. My mother is a marine biologist. D. NO CHANGE

The correct answer is: C. My mother is a marine biologist. This answer is the most concise of all the answers, avoiding unnecessary words. Many ACT questions try to confuse you with complex wording and unnecessary words that may seem like they sound smarter or more sophisticated, but often times, the correct answer is the simplest one that gets the point across without any fluff. Answer A is incorrect because saying the mother is a marine biologist already implies that she has an interest in science. Similarly, answer B is also incorrect because it adds unnecessary words, as it is obvious that being a marine biologist is the mother's occupation. Answer D is incorrect because saying "Having studied" at the beginning of the sentence is wordy and also unnecessary.

### Subject: Algebra

Andrea and Brian work for two different companies that sell children's toys. Andrea works for Company X and Brian works for Company Y. Company X pays Andrea a base-pay of $30 per day that she works, plus a commission of $5 per sale that she makes. Company Y pays Brian a base-pay of $60 per day that he works, plus a commission of $3 per sale that he makes. How many sales does Andrea have to make in a day to make more money than Brian makes for the same number of sales? Hint: Set up a system of equations to start!

As hinted, we must first set up a system of equations to answer this question. One of the most important things in helping algebra make sense for students is to understand what the numbers and letters of an equation mean in words. We can set up the following system of equations: p = 5x + 30 p = 3x + 60 where the first equation represents Andrea's pay and the second Brian's. In the equations, p represents the total pay they receive in a day, and x represents the number of sales they made. We multiply x by the commission payment because for every sale x that Andrea or Brian make, they get payed the commission ($5 or $3). Then we add 30 and 60 to each of the equations because that is the base pay that they will make in a day regardless of how many sales they make. Next, we can set the two equations equal to each other to see how many sales each of them would have to make in order to make the same amount of money: 5x + 30 = 3x + 60 Then, we solve for x by subtracting 3x from both sides, subtracting 30 from both sides, and then dividing both sides by 2: 5x - 3x + 30 = 60 2x + 30 = 60 2x = 60 - 30 2x = 30 x = 15 Now that we have solved for x, we know that the number of sales Andrea and Brian have to make in order to make the same amount of money is 15 sales. Therefore, in order for Andrea to make more money than Brian in the day, she would have to make 16 sales. To check our work, we can plug in 16 to the equations, which gives Andrea $110 and Brian $108. We can also plug in larger numbers to check to make sure it will continue to work. For example, if we plug 20 into both equations, Andrea would make $130 and Brian would make $120. Final Answer: 16 Sales