Which of the following elements is a lanthanide?
- A) Samarium
- B) Neodymium
- C) Plutonium
- D) Uranium
Answer: A) Samarium
Which element in Period 5 has the electron configuration [Kr] 5s² 4d¹⁰ 5p²?
- A) Tin
- B) Lead
- C) Indium
- D) Antimony
Answer: A) Tin
Which of the following elements is in Period 6 and has an electron configuration ending in 4f¹⁴ 5d¹⁰ 6s²?
- A) Samarium
- B) Neodymium
- C) Dysprosium
- D) Gadolinium
Answer: D) Gadolinium
Which element has the electron configuration [Xe] 6s² 4f⁶ 5d¹?
- A) Samarium
- B) Neodymium
- C) Dysprosium
- D) Gadolinium
Answer: C) Dysprosium
Which of the following is an alkali metal in Period 4?
- A) Rubidium
- B) Potassium
- C) Sodium
- D) Cesium
Answer: B) Potassium
Which element in Group 2 has the lowest ionization energy?
- A) Beryllium
- B) Magnesium
- C) Calcium
- D) Strontium
Answer: D) Strontium
Which of the following elements has the electron configuration [Ar] 4s² 3d¹⁰ 4p⁵?
- A) Chlorine
- B) Bromine
- C) Iodine
- D) Selenium
Answer: B) Bromine