So, here's the thing, I was unemployed for a several months after graduation, and shortly after, I was offered with 2 jobs position (both office location are really far away from each other, company A in capital city, company B in country-side).
First, both companies, let's say company A and B, offers medium salary, and because company A approach me first, with no hesitation I accept the offer, and I like both company job desk.
One month has passed, and suddenly company B called back and raised up their salary offer above my expectation, literally, I am tempted to resign from my current employer (company A) but have no idea on how to communicate it with the company.
Professionally speaking, what should I say to the company HR regarding this matter? Without me sounding like an ungrateful employee, given I'm still just an 'fresh graduate'. (note: I was given the opt to 'one month notice')
Addition:
Also, do I have to give some sort of email notice (when I leave) to all employee (company A only have a handful of employee, so I know most of them in just a short time) or just a few colleagues I'm close to?
Company A has taken liberty to pardon my absence (for 3 days) when it's should be my first day working, because of family issues, I feel grateful for this.
Company B has called me in my first week working at company A, asking about their offer, and I refused the offer back then, but they called back again.