A decay has a half life of 2.60 years, what mass of 72.5 g sodium-22 will remain after 15.6 years

What semimetal can form four single covalent bonds.

Can someone me with questions 12 and 13 plz.

*will mark you brainliest + 15 points ** why does the equilibrium of a system shift when the pressure is increased? a. to maximize the stress on the system b. to stop restoring equilibrium to the system c. to increase the total moles of gas in the system d. to decrease the total moles of gas in the system