Facebook CEO Mark Zuckerberg and his wife, Priscilla Chan, are donating $120 million to the San Francisco Bay Area's public school system.

The couple's gift will be spread over the next five years and is the biggest allocation to date of stock the couple pledged last year to the nonprofit Silicon Valley Community Foundation.

The gift comes at a time when critics are still questioning what became of Zuckerberg's $100 million donation to Newark, New Jersey's public school system.

While well-intentioned, the money has so far failed to fix anything.

The process lacked meaningful community input and much of it has been spent on high-paid contractors and consultants.