Your answer would be "Chemical Change"
Steroids are lipids because they are hydrophobic and insoluble in water
69. The student's skin was obviously warmer than the initial temperature of the bracelet. According to the second law of thermodynamics, heat transfers from a higher temperature to a lower temperature hence heat transfers from the student's skin to the bracelet warming up the bracelet.
70. moles of copper=mass of copper/molar mass of copper
=30.1g/(63.55g/mol)= 0.4736 moles Cu
71. Delta H( heat released) = mCp(deltaT) = 30.1g(0.385 J/gK)(33-19)K = 162.23J
72. Copper is chemically less active than iron.
Following are the chemical elements that have atomic mass greater than 173.5 u and atomic number less than 75.
1. Lutetium
Atomic Number = 71
Atomic Mass = 174.97 u
2. Hafnium
Atomic Number = 72
Atomic Mass = 178.49 u
3. Tantalum
Atomic Number = 73
Atomic Mass = 180.95 u
4. Tungsten
Atomic Number = 74
Atomic Mass = 183.85 u
