PLZZ HELP THIS ON A TEST!! What is Half-life?

Question 15 options:

The amount of time it takes for half the nuclei in a sample of the isotope to become radioactive

The amount of time it takes for half the nucleus of the isotope to decay

The amount of time it takes for half the nuclei in a sample of the isotope to decay

the amount of time it takes for half the number of protons in the nucleus to decay

Protein synthesis actually begins in the nucleus when transcribes a single gene on the dna molecule is copied. the process of copying this gene is called this copy is known as and contains the protein building instructions. this copy is sent out into the cytoplasm to the part of the cell known as the the of the ribosome will join together to form a functional ribosome when they attach to the mrna. as the mrna moves through the ribosome, the message is read by transfer rna brings the correct back to the ribosome. the amino acids are placed in the correct order and are hitched together by

Ricardo notices that when he plays soccer in the rain, his ball does not seem to go as far after a kick. what is the best scientific question that ricardo could ask about this observation? is soccer better played in the rain or sun? how does rain affect the distance a soccer ball can travel? how does rain affect the speed of a soccer ball? is soccer affected by the rain?

Predict the results of a two base insertion or deletion in a strand of dna that codes for a protien, how does this differ from a three base insertion or deletion?