Background Info: A radioactive isotope is an element that has a nucleus that is so unstable, that
it causes the substance to decay into a different
element. The half-life of a radioactive isotope is how
long it will take for that substance's mass to
decrease by half. Explained differently, after 1 half-

life period of time, 50% of the substance is gone.
The exponential decay equation used to determine
how much of a substance that is left, y, is:
a
a is the starting mass
x is the number of half-lives that have passed.
(EX. If the half life is 3 days, then 6 days would be 2
half lives and 9 days would be 3 half-lives)
y = a(0.5)*
=
Question 9 (1 point)
Arsenic-74 is used to locate brain tumors. It has a
half-life of 17.5 days. 90 mg were used in a
procedure. Write an equation that can be used to
determine how much of the isotope is left after x
number of half-lives.

Please help me it’s so confusing!!

The verbal translation for the difference of m and 7 increased by 15

First to answer all gets a donation question 3(multiple choice worth 1 points) (04.01 lc) which of the following levels is lower than cells in the hierarchy of organization of living things? molecules organs organ systems tissues question 4(multiple choice worth 1 points) (04.01 lc) which of these represents an individual form of life such as an animal, plant, or single-celled life form? organ organism organ system tissue question 5(multiple choice worth 1 points) (04.03 lc) what are the green structures inside plant cells where photosynthesis takes place called? chloroplast mitochondrion nucleus vacuole question 6(multiple choice worth 1 points) (04.03 lc) which of the following best matches a part of a living cell with the function it performs? cytoplasm: fluid which carries the nucleus and other organelles vacuole: fluid which carries the nucleus and other organelles cytoplasm: directs all of the cell's activities vacuole: directs all of the cell's activities question 7(multiple choice worth 1 points) (04.03 mc) read the table below. organelles of plant cells present in both plants and animals present in plants but not animals small in animals but large in plants organelle a organelle b organelle c which statement is most likely correct? organelle a is chloroplast, organelle b is cytoplasm, and organelle c is nucleus. organelle a is mitochondrion, organelle b is cytoplasm, and organelle c is nucleus. organelle a is cell wall, organelle b is chloroplast, and organelle c is mitochondrion. organelle a is mitochondrion, organelle b is chloroplast, and organelle c is vacuole. question 8(multiple choice worth 1 points) (04.03 mc) what will most likely happen in the absence of a nucleus? genetic information will not be transmitted by the cell. energy will not be released during cellular respiration. the cell will not store food, water, nutrients, and waste. the cell will lose its shape and structure.

Can somebody 1. what is the formula for finding the vertical distance between two points on a coordinate plane?