Which of the following describes an atom

Is dissolving salt a chemical change or physical change and why?

Why does the presence of lone pairs contribute to the polarity of a water molecule

Instructions for all body activities are found in a chemical known as

The following balanced equations represent double replacement reactions that each result in the formation of precipitation.

An unknown sample weighing 28.26g contain 70% of hydrogen and 30% of carbon calculate the [1]empirical formula [2]the molecular formula [3]give the iupac name of the compound

What is the final product of the following sequence of reactions? A. A B. B C. C D. D 21. Which of the following reacts the fastest with NaOH, H2O? A. ethylene oxide (oxirane) B. cis-2,3-dimethyloxirane C. trans-2,3-dimethyloxirane D.

Which best describes the function of the structure labeled y

Which statement is a valid conclusion about the activation energy of the reverse reaction if the forward reaction is exothermic? a) The activation energy of the reverse reaction is the same as that of the forward reaction.

Why are metallic and ionic substances harder to melt than covalent substances

In general, ionization energies increase across a period from left to right. Explain why the second ionization energy of Cr is higher, not lower, than that of Mn.