I just wanted to find out if the use of google form is a scientific method in collection of data in respect to simply sampling, stratified sampling or purposeful sampling....
Yes, if the data is obtained correctly using Likert scales because it is survey data. It must be analysed with non-parametric tests, such as Chi Square :)
The means of collecting the data shouldn't impact your sampling. You can use any of the sampling methods you mentioned with Google Forms. However, you'll have to consider if Google Forms is a secure way of collecting the data as it may raise privacy concerns.