Select all that apply to the property of hardness. Hardness is indicative of the strength of chemical bonds between elements.
Hardness is determined through a complicated process that requires expensive instruments.
Hardness is a physical property
Diamond can scratch quartz.
Friedrich Mohs developed the standard hardness scale.

11. phosphorus-32 is radioactive and has a half life of 14 days. how much of a 124 mg sample of phosphorus-32 is present after 56 days? a) 7.75 mg b) 15.5 mg c) 31.0 mg d) 62.0 mg

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.

Explain how global warming could have affected yellowstone frog and salamander habitat's, resulting in changes in the populations of these species