Calculate the volume of oxygen in excess when 20cm3 of hydrogen is sparked in 15cm3 of oxygen at a temperature of 1500C according to the following equation:
2H2(g) + O2(g)  2H2O(g)

How are elements arranged in a periodic table

Question 3(multiple choice worth 4 points) (04.04 lc) what does it mean when an element is reduced? it empties a valance shell, reducing its atomic radius. it gains electrons, reducing its overall charge. it increases electronegativity, reducing its ability to bond. it loses electrons, reducing its electron number.

Which of the following is not true about the atomic model of substances?