How would you find the number of neutrons in an atom? subtract isotope number from atomic number

subtract the mass number from the atomic number

subtract atomic number from mass number

add the atomic number and mass number

The brightest star in the night sky in the northern hemisphere is sirius. its distance from earth is estimated to be 8.7 light years. a light year is the distance light travels in one year. light travels at a speed of 3.00 × 108 m/s. calculate the distance from earth to sirius in miles. (1 mi = 5280 ft) g