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.
VisaÂ®, MastercardÂ®, and DiscoverÂ® cardholders: Turn your card over and look at the signature box. You should see either the entire 16-digit credit card number or just the last four digits followed by a special 3-digit code. This 3-digit code is your CVV number / Card Security Code. American ExpressÂ® cardholders: Look for the 4-digit code printed on the front of your card just above and to the right of your main credit card number. This 4-digit code is your Card Identification Number (CID).