Which element would most likely be a shiny solid at room temperature and have a high density? kr or br cu or f

What are the resulting coefficients when you balance the chemical equation for the combustion of ethane, c2h6? in this reaction, ethane is burned in the presence of oxygen (o2) to form carbon dioxide (co2) and water (h2o). (g)+(g)→(g)+(g)

Iknow #2 is d. i just need to know why

Complete the sentence. the lower the hydrogen ion concentration, the the ph. higher lower closer to 7 closer to 0