A scapegoat is someone who is blamed for something which is not his/her fault. People offload their own guilt or responsibility onto him/her. The scapegoat excluded, punished, even killed.
A scapegoat is usually the victim of prejudice of some kind.
There may be a scapegoat in a family: it’s her fault we lost all our money. Or it may be in the team: he let them score that goal. Or, more seriously, people may blame all their problems on a teacher or parent, or politician.
The scapegoat may be political. We all remember the way Hitler blamed ‘the Jews’ for all his country’s problems. Or it may be ‘immigrants’ or ‘benefit scroungers’, and so on, or the people of a country ‘we’ are at war with.
Or scapegoats may be social. Women are often blamed for declines in moral standards. It’s possible that sometimes the people blamed may actually be the guilty ones, but we wouldn’t call them ‘scapegoats’ in that case. Or would we?
Or scapegoats may be religious. Jesus was a scapegoat. In some countries being of the ‘wrong’ religion is dangerous. People think you are sly, sneaky, disloyal, and so on.
WRITE SOMETHING ABOUT A SCAPEGOAT
In this you need to work on the tone of voice of the speaker. Write a ‘talking heads’ piece from the point of view either of the scapegoat victim, or the prejudiced person. The voice should not be your own. Try to ‘act’ the smug prejudiced person talking, or the unhappy scapegoat complaining.