Which statement is true? a. a sample statistic can never be equal to the population parameter. b. point estimates are defined for both samples and populations. c. to calculate a sample proportion, we need to know the population size. d. to calculate a point estimate, we need to know the sample size

Easy definition for atom and atomic mass

I'm learning about the periodic tables and what each subject's configuration is. for example, hydrogen is 1s^1, but i don't understand how you get that. can someone me understand how to figure out how to figure this out? sorry if the question makes no sense, but it would really a lot if you could me understand! you so much if you can!

Molecular iodine, i2(g), dissociates into iodine atoms at 625 k with a first-order rate constant of 0.271 s−1. part a part complete what is the half-life for this reaction?