Very useful, thank you for your suggestion.
But, I read articles about science on various sites, then I assemble and write in my article, more details, I quote.
About the image, why I write Source image / referance? because there I get about the science I write. So, I put the image address, as well as a reference from my writing.
if it's against the rules, how should I get a free image?
I am not a researcher, and I also do not have a laboratory to take pictures as sample.
Give me guidance.
Let us know what sites you used, that way we can read a bit more about the topic.
Have a read about fair use images and creative commons. Wikimedia is a good place to find a lot of images, most of mine are from here.
I have seen and read your article on this one: https://steemit.com/steemstem/@physics.benjamin/the-wonders-of-the-electro-magnetic-spectrum-light-interaction-why-you-see-the-colours-you-do
now I understand, I will do it in my writing in the future.
thank you for your suggestion, this is very useful for my writing.
Personally, I can recommend using PixaBay and Pexels.
They offer "free", "CC0" images. (Creative Commons, 0)
And Wikipedia can be a good source of "CC-BY-SA". (Creative Commons, By Name, Share Alike)
Here, simply state
Par example:
"Mr. Ding Dong, Wikipedia, CC-BY-SA. [Hyperlink to source]"
"PixaBay.com, CC0 License. [optional Hyperlink to source]"