The Greek letter δ (delta) is used to signify . a) an ion
b) a charged particle
c) a mixed number
d) a small fraction
e) none of the above

Why does the sun appear to be the brightest star in the sky? a- its apparent brightness is much greater than other stars. b- it burns more gas, making it brighter than any other star. c- it is the largest star in the galaxy, so it is the brightest star. d- its relative distance to earth is closer than the other stars.

When the chemicals iron sulfide (fes) and hydrochloric acid (hcl) are combined, bubbles appear from the mixture. 1. does the appearance of bubbles indicate a physical or chemical change? 2. why do the bubbles indicate this change? 3. what property is this?

How many neutrons does an element have if its atomic number is 50 and its mass number is 166