Predict a simple reaction from the outer electrons
Grade 10 Science Worksheet - Building Confidence
Circle the best answer, or write your answer on the line.
Sulfur is in group 16. How many electrons does one sulfur atom gain to reach eight outer electrons, Ari?
Nitrogen is in group 15. How many electrons does one nitrogen atom gain to reach eight outer electrons, Bo?
Chlorine is in group 17. How many electrons does one chlorine atom gain to reach eight outer electrons, Esme?
Aluminum is in group 13. Which ion is it predicted to form, Jun?
- Al³⁻, after gaining 3 electrons
- Al¹³⁺, copying the group number
- Al³⁺, after losing its 3 outer electrons
Sulfur is in group 16. Which ion is it predicted to form, Kira?
- S²⁺, after losing 2 electrons from its outer shell
- S⁶⁻, gaining its 6 outer electrons again
- S²⁻, after gaining 2 electrons to reach eight
Lithium and potassium each have 1 outer electron. Which reacts more vigorously with water, and why, Milo?
- Neither: the same number of outer electrons means the same reactivity
- Potassium: its outer electron is farther from the nucleus, so it is lost more easily
- Lithium: its smaller atom holds its outer electron more loosely
Fluorine and iodine each gain 1 electron. Which pulls in an electron more strongly, Noah?
- Fluorine: its outer shell is closest to the nucleus, so the pull is strongest
- Iodine: it has more electrons, so it pulls a new one in harder
- Both pull equally, since each needs exactly 1 electron
Sodium reacts with chlorine in a 1 to 1 pattern. Which other element should react with chlorine the same way, Pia?
- Potassium, which also has 1 outer electron
- Aluminum, the next metal along the same row
- Magnesium, which sits right beside sodium in the same row
Calcium (group 2) combines with chlorine (group 17). Which formula is predicted, Tala?
- CaCl, because one of each pairs them
- Ca₂Cl, because the subscripts swap places
- CaCl₂, because one Ca²⁺ needs two Cl⁻
Lithium (group 1) combines with oxygen (group 16). Which formula is predicted, Zee?
- LiO, because one of each pairs them
- LiO₂, because the subscripts swap places
- Li₂O, because two Li⁺ cancel one O²⁻