a group of students working in a high school chemistry lab believe they have discovered a new element! how exciting! upon further testing by scientists (with better equipment), it is found that the new element contains 74 protons and 110 neutrons. use page 495 and the periodic table (pages 500-501) to answer the following questions about this new element.
1. what is the atomic number of this element?
2. what is the mass number of this element?
3. is this really a new element? explain your reasoning.
4. give the name and symbol for this
5. when the students discovered it, did they find a solid, a liquid, or a gas? explain your reasoning.
6. explain why a chlorinated swimming pool water would be a homogenous mixture? (pages 465-467)
7. both slicing an apple and a chemical change such as cooking an egg cannot be reversed. however, why is slicing an apple still considered only a physical change? (pages 471-472)
for questions 8 and 9, refer to pages 434-435.
if an ice cube melts at 0oc but water also freezes at 0oc, what is the difference between melting and freezing in terms of…….
8. the energy involved in the phase changes and
9. the motion of the particles of the substances during the phase changes?