What happens when a substance undergoes a physical change?
Some physical properties change, but the substace keeps its identity.
No physical properties change, and the substance keeps its identity.
Some physical properties change, and the substance changes its identity.
No physical properties change, but the substance changes its identity.

Darla claims that the first periodic table developed by mendeleev was not completely accurate, so it is not useful at all. harmony argues that it establish the periodic table we use today, making it more credible. who is correct and why? darla is correct, because a model that has any mistakes should be thrown out. darla is correct, because a good model would not need to change. harmony is correct, because mendeleev’s model had all of the information correct in the first version. harmony is correct, because mendeleev’s model made predictions that came true.

1)each group 16 element has how many valence electrons? ( )4 ( )6 ( )8 ( )16 2)how many dots appear in the dot structure for calcium ion, ca2+? ( )zero ( )one ( )two ( )eight 3) which of the following atoms forms a cation to obtain an octet of outer shell electrons? ( )magnesium ( )oxygen ( )fluorine ( )helium 4) an al3+ ion contains 13 protons and 10 electrons. ( )true ( )false 5) valence and non-valence electrons are represented in lewis dot structures. ( )true ( )false

Someone offer some answers to this, i will give 98 coins and mark as brainliest! i will put the rest of the lab down in the comments,solutions pre-lab questions: in this lab, you will make fruit drinks with powdered drink mix. complete the pre-lab questions to get the values you need for your drink solutions. calculate the molar mass of powered fruit drink mix, made from sucrose (c12h22o11).using stoichiometry, determine the mass of powdered drink mix needed to make a 1.0 m solution of 100 ml. (hint: use molarity = to find the moles of drink mix, then convert moles to grams using a mole conversion.)what mass of powdered drink mix is needed to make a 0.5 m solution of 100 ml?