It's going to depend on what you want to do with it, really.
Windows laptops come in lightweight versions too (eg. Ultrabooks). With Solid State drives (SSD) becoming so prevalent, weight becomes less of a factor.
Yes, chromebooks tout cloud storage (which you can subscribe and pay for), but they do have local storage too. Those 32gb / 64gb drives, thought, are very slow. If a hard drive is a car (depending on the model, could be a corvette could be a hyundai accent), that drive in a chromebook is a bicycle. They are often confused with SSDs... They aren't even close.
The processors in most lowend chromebooks are going to be very lackluster (just like in budget PCs)... Like Dave found out with his inability to zoom. Low, entry level chromebooks are really meant for simple 1-2 tab browsing (and other simple tasks).
Additionally, a chromebook runs Chrome OS, whereas an Android runs Android OS. Different animals. Early on a chromebook was basically a self sustained browser with a few tricks up it's sleeve. Nowadays most chromebooks can also run some (most?) Android apps. Keep in mind, I don't think it's running them native. What I'm getting at is your may have bugs and compatibility issues, and it may not be stable (not that all apps are stable on my Pixel anyway, lol).
You should look online for reviews. Weights are absolutely included in specs, so that won't be a surprise. If you want to be able to do more than a few tab browsing, look for something with a decent processor. An Intel i-series is a great place to look and an i3 should be obtainable for a good price, if you hunt around. Also steer towards 4+ GB ram. That way, It'll definitely handle most tasks you throw at it (and then some). If you lean towards a windows 10 laptop, make sure it has a SSD and 8gb ram, too.
Good luck!