When solid changes directly into a gas, a change called occurs.
a. physical; boiling
b. chemical; boiling
c. physical; sublimation
d. chemical; sublimation

100 points answer quick 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.

Frictional forces acting on an object are often converted into energy, which causes the temperature of the object to rise slightly.

Use examples from the article to explain one positive and one negative effect that chemistry has had on society.