Most junior high school science classes broadly cover the natural science, from basic physics, chemistry, earth sciences, and biology. Grasping so many concepts can be tricky, though, so if you need homework help for 8th grade science, you should consider these following points.
Junior high (especially 8th grade) is the time when schools change from general ideas to specific concepts in terms of teaching science. Teachers are preparing you for high school the more rigorous science classes you will take in high school. Therefore, it is vitally important that you start building good study habits ASAP. Up until this point in school, you could probably get by without studying or readying the book too closely. Well, not anymore. It is really important to read the assigned chapters in the book and understand what the book is saying. Also very important is to do the homework and understand what you're doing! You will eventually be tested on the material covered in homework--that is a guarantee.
If you believe you're spending enough time reading the book but aren't getting the grade you want, you should consider getting homework help for 8th grade science from another source, be it your parents or a tutor. If you're already spending 4-6 minimum per week studying (that should probably be enough studying to get an A in most junior high science classes), then you need to seek outside help. A tutor can quickly help you get back on track with the concepts from class. Ask your teacher if you are looking for and can't find additional homework help.
This next point should be self explanatory, but I'm not at all surprised at how many students don't already do this--and this is that you need to pay attention in class. If you're sleeping or talking during class, not only are you going to miss what the teacher is telling you, but you're not even going to know WHAT topics have been covered in class. It is extremely difficult to study for a test if you don't know what topics to study for! Things you need to do to pay attention in class include getting enough rest (8 hours is recommended), eating enough for breakfast and lunch, and being prepared with paper and pencil. And a trick that will help you far into the future is to read the material ahead of time. When you hear the teacher talking about material you've already heard, it'll make SO much more sense. Following these tips will make science class easier to learn and reduce the amount of homework help for 8th grade science class that you'll need.