Brainliest answer!an earth-like planet is 500 light years away. why is this an obstacle for a manned space mission?

a. the cost is too low
b. there is no oxygen in space
c. humans cannot live for 500 years
d. there are no plans to send a human

Is pain reliever a prescription drug?

Which of the following elements would you expect to have the lowest ionization energy value? fluorine, lithium, neon, nitrogen

With the largest atoms and the smallest number of valence electrons and with the smallest atoms and the greatest number of valence electrons are the most reactive. a. nonmetals; metals b. nonmetals; transition elements c. transition elements; metals d. metals; nonmetals