Headphones let a single user listen to an audio source privately, in contrast to a loudspeaker, which emits sound into the open air for anyone nearby to hear. Headphones are also known as earspeakers, earphones or, colloquially, cans. Circumaural and supra-aural headphones use a band over the top of the head to hold the speakers in place. The other type, known as earbuds or earpieces consist of individual units that plug into the user's ear canal. In the context of telecommunication, a headset is a combination of headphone and microphone.
Osmium is usually sold as a minimum 99.9% pure powder. Like other precious metals, it is measured by troy weight and by grams. Its price in 2012 was about $400 per troy ounce (or about $13,000 per kilogram), depending on the quantity and its supplier.
Answer 1: Osmium is the most dense metal! Many people are familiar with lead (11.3 kg/mL), but osmium is twice as dense (22.6 kg/L)! Each liter (about 1/4 gallon) of osmium weighs 22.6 kg (50 lbs).For comparison, each liter of water weighs only 1 kg (~2.2 lbs).Some other heavy metals include tungsten and gold (19.3 kg/L), which are almost as dense as osmium. There are a lot of numbers, but sometimes it's tough to make sense out of these.ach liter (about 1/4 gallon) of osmium weighs 22.6 kg (50 lbs). For comparison, each liter of water weighs only 1 kg (~2.2 lbs). Some other heavy metals include tungsten and gold (19.3 kg/L), which are almost as dense as osmium. There are a lot of numbers, but sometimes it's tough to make sense out of these.