the deliberate killing of a large number of people from a particular nation or ethnic group with the aim of destroying that nation or group.
The aim of Israel isn’t to destroy Palestine or kill all Palestinians. They definitely want to destroy Hamas, maybe they want to take over Gaza. While their tactics are inhumane and kill many Palestinians, I don’t see how you could argue their real goal is to kill Palestinian as an ethnicity. Abou 20 % of the citizens in Israel are Palestinian. And they also do not attack the Westbank.