Why were some Jews in concentration camps killed and not others?

Most were killed. Others were shipped to concentration camps...then killed.

concentration camps were some were killed while others worked

Jews were generally sent to extermination camps. Many were killed on arrival, others were worked to death. Very few survived.

they killed jews and other people

Overall about six million Jews were killed in the Holocaust. About half of the victims were killed in extermination camps and concentration camps, and the other half in mass open air shootings 'in the field' and by starvation in ghettos.

concentration camps were places where Jews were kept in the 2nd world war and then the used to get killed there

Historians believe there was about 6 million Jews that died during the holocaust in the camps

Hitler and the Nazis did not bury the Jews that they killed. The Jews who were killed in the concentration and extermination camps were cremated. Others, who were shot, had to dig mass graves themselves and they were then killed in such a manner that they would just fall into the mass graves.

they killed the jews mostly by them going into gas chambers

Hitler killed Jews, Nazis killed them, there were torture devices, and concentration camps. Many more things too.

About 4.5 million of those who died in the Holocaust were killed in the camps.

The total number of Jews killed by the Nazis was about 6 million. Just over half of these died in extermination and concetration camps. The others were killed in mass open air shootings or perished from starvation and disease in ghettos.

There were about 1,500 concentration camps and they were not just for Jews.

they were being relocated to concentration camps,where they got killed.

No. They were tortured and killed.