PLEASE HELP PLEASE!!ASAP!

Apiece of metal with a length of 1.42 cm was measured using four different instruments. which of the following measurements is the most accurate?

16. why must the number of electrons lost equal the number of electrons gained in every redox reaction? use 3 – 4 sentences in your own words to address this question. 18. what type of radiation is emitted when chromium-51 decays into manganese-51? show the nuclear equation that leads you to this answer. 19. a radioactive nucleus alpha decays to yield a sodium-24 nucleus in 14.8 hours. what was the identity of the original nucleus? show the nuclear equation that leads you to this answer.

What is happening when the water inside a kettle heats up and begins to boil