What is the half-life of this substance?

His encouraging words give me courage.

He lost everything.

She is planning a date with her current boyfriend.

My boyfriend gave me a gift.

Everyone was surprised by the news.

He has a competitive spirit that does not allow even one defeat.

I withdrew money from the automatic teller machine.

He likes to take a walk in the park at dusk.

Take care until the day we meet again.