Which of the following has the longest half-life? a. 0-19
b. H-3
c. Zn-71
d. Rb-85

How many oxygen atoms are there in 3.15 moles of hcl manganese (iv) oxide, mno2

Covalent bonds generally form when the bonded elements have a difference in electronegativity less than 1.5. subtract the electronegativities for the following pairs of elements and predict whether they form a covalent bond. electronegativity difference of c and c: ionic covalent electronegativity difference of mg and cl: ionic covalent

2. what two items do autotrophs take from the environment to produce their food? 3. what are the two items that are released during transpiration from leaves? 4. what are the two membranes of the system? a.what are the two stages of photosynthesis? what are the two parts of photosynthesis?