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.
CVV stands for Card Verification Value (Discover Card calls it the Cardmember ID). 1  It is the three-digit number printed in the signature space on the back of most credit cards, such as Visa, Mastercard, and Discover cards.2  It is a four-digit number on the front of American Express cards. It is the three-digit number printed in the signature space on the back of most credit cards, such as Visa, Mastercard, and Discover cards. 2  The CVV2 number is always the last group of numbers in the signature space on the back of the card. 3  It is not part of your regular credit card number.