What does the law of conservation of mass state?
a. mass cannot be created nor destroyed in a chemical reaction.
b. mass can be created and destroyed during a chemical reaction.
c. mass can be created but not destroyed in a chemical reaction.
d. mass can be destroyed but not created during a chemical reaction

The table compares the number of electrons in two unknown neutral atoms. comparison of electrons atom number of electrons a 10 d 11 use this information to determine the number of valence electrons in the atoms. which of the following correctly compares the stability of the two atoms? both are unreactive. both are highly reactive. a is unreactive and d is reactive. a is reactive and d is unreactive.

At stp, which substance is the best conductor of electricity? a. nitrogen b. neon c. sulfur d. silver

Which of these statements best explains why space exploration should be encouraged? it prepares humans to live without oxygen. it dispel myths about objects in space. it prevents comets and asteroids from striking earth. it creates technology to absorb harmful radiations in space.