The heat for melting or freezing water, also called the Heat of Fusion (Hf), is 80 calories per gram at 0Â°C, which is the equilibrium temperature. In other words, it is necessary to add 80 calories of energy to melt one gram of ice at 0Â°C.
The CVV Number (Card Verification Value) on your credit card or debit card is a 3 digit number on VISAÂ®, MasterCardÂ® and DiscoverÂ® branded credit and debit cards. On your American ExpressÂ® branded credit or debit card it is a 4 digit numeric code.
The CVN code (or CVV2/CVC2) is a special 3-4 digit code used as an additional security measure for online transactions. On most cards, this number is a 3-digit code on the back of your card, near the signature strip. On American Express cards, the 4-digit code is above and to the right of your card number on the front of the card.