WATCH: These are the top 5 deadliest substances on Earth
• http://www.sciencealert.com"Just 500 micrograms of the stuff - that's five ten thousandths [0.0005] of what a paper clip weighs - is enough to kill a man,"
"Just 500 micrograms of the stuff - that's five ten thousandths [0.0005] of what a paper clip weighs - is enough to kill a man,"