David’s mom wants to calculate how much it will cost to drive from Los Angeles, CA, to San Francisco, CA. Gas costs $4. 00 a gallon, and the gas mileage of their car is 38 miles/gallon. What additional information does David’s mom need to do this calculation? the size of the gas tank the distance between the two cities the number of times that the gas tank will be filled along the way the speed limit on the highway between the two towns.

Ahydrogen atom has 1 electron. how many bonds can hydrogen form? a) 1 b) 2 c) 3 d) 4 e) 5

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.)

Element before carbon on the periodic table