Which isotope of hydrogen is unstable

Hydrogen has three naturally occurring isotopes: 1H (protium), 2H (deuterium), and 3H (tritium). Other highly unstable nuclei (4H to 7H) have been synthesized in the laboratory, but do not occur in nature. The most stable radioisotope of hydrogen is tritium, with a half-life of 12.32 years.

Explanation:

i really hope i helped ya out! good luck!

1. 1 mole of anything contains 6.022x10^23 pieces  

d  

2. a  

3. c, number  

5. 1.24x10^24atoms / 6.022x10^23atoms/mole = 2moles h2 atoms  

6. fe2br3 mass = 2moles x mass fe + 3 moles x mass br  

molar mass = grams / number of moles = g/mole  

to find moles = g / molar mass  

to find mass = g = molar mass / moles