Answer:
1. 17 protons / 10 neutrons
2. Scandium
3. Negative
Step-by-step explanation:
1. The bottom number is the same as the atomic number on top of the abbreviation. To find the # of neutrons, subtract the mass number with the number of protons
2. The bottom number (21) is the number of protons AND the atomic number (the a.n & # of pro. are always going to be the same)
3. Always think about this: if you add electrons, you take away charge - if you take away electrons, you add charge
*Idek if these were the correct correct answers but I tried my best*