What is the most common oxidation state of lanthanides?

Which of the following is not a very hard metal?

Which of the following is not a property of a transition metal?

Which of the following is amphoteric?

What is the common oxidation state of scandium? (At. No. of Sc = 21)

Which of the following element is not a transition element?

Which is the most stable oxidation state of actinoids?

Sc3+ is a paramagnetic ion.