None of them.
An ounce (not once) will measure its mass. To get weight you need ounce-weight.
a postage scale or nutrition scale
I would measure its length in inches, its weight in ounces, and its screen brightness in lumens.
The answer varies immensely from location to location based on the size of a given city.
mm
Phone: 1-800-997-6917
Weight Watchers has a phone app that allows you to track your weight loss and measurements, which can be helpful to staying motivated and on track.
The average weight of a cell phone is 200grams - 800grams otherwise it's to heavy or light!
Probably inches or centimeters.
7 billion tonnes.
it depends on type of phone like before 2000 the phones were heavy but now phones are slim and weight like 100 g
The best unit of measurement for the weight of a phone book would be in pounds or kilograms, depending on your location's preferred system of measurement.
1-800-651-6000