Easy periodic table question, pls help What are columns (up and down) of the periodic table called? How does the element’s column relate its number of valence electrons?

In salt water solution,the salt is the blank

Select the correct answer a modure consists of glucose and water. what is the percent composition of glucose in the mixture if it contains 1.3 moles of glucose (cho total mass of the mature is 276 grams? ) and the a 1775

Suppose you mix one mole of sulfuric acid (h2so4) with 1 mole of sodium hydroxide(naoh). why does the ph of the solution remain below 7? ( explain so i can get better understanding! )