a good scientific experiment has the following characteristics:

1. it answers a testable question.
2. it answers a well-defined question.
3. it is systematic.
4. it is controlled.

for each of these four characteristics, explain in your own words what it means, and what would likely happen if an experiment did not have that characteristic.

1. You can't test something that you don't have the means to find the answer. For example: You can't test how mustard effects cell growth if you have no way of seeing the cells.
2. The question you are trying to answer should be understandable so people know exactly what it is you are trying to answer.
3. It has a process and the steps are easy to follow so it can be replicated accurately for the purpose of further research.
4. It is done in a way that makes sure no unexpected things cause change to the outcome. It's like when you're trying to find what you're allergic. You don't eat a bunch of foods and wait for a reaction, you eat one thing at a time so that way you're not missing any factors.

Does that make sense?

Alpha particles have positive charge, beta particles have negative charge, and answer 4 just doesn’t make sense. thus, you are left with only one possible answer.