30)
experts estimate that over 25,000 species become extinct each year, with some estimating this number to be over 100,000. this is an alarming rate that threatens fragile ecosystems and global biodiversity. which of these is currently the leading cause of extinctions today?
a) global climate change
b) habitat loss due to human interactions
c) development of cleaner running automobiles
d) natural disasters such as volcanic eruptions and earthquakes

Which element would mostly likely have an electron affinity measuring closest to zero

Modern pennies are composed of zinc coated with copper. a student determines the mass of a penny to be 2.482 g and then makes several scratches in the copper coaling (to expose the underlying zinc). the student puts the scratched penny in hydrochloric acid, where the following reaction occurs between the zinc and the hcl (the copper remains undissolved): zn(s) + 2 hcl(aq) → h2(g) + zncl(aq)the student collects the hydrogen produced over water at 25 °c. the collected gas occupies a volume of 0.899 l at a total pressure of 79 j mmhg. calculate the percent zinc (by mass) in the penny. (assume that all the zn in the penny dissolves.)

If anyone would be able to me out with these three questions it would be these are from the chem 2202 course.