Which pair of elements have the same amount of valence electrons lithium, beryllium, sodium, magnesium

In a reaction (at equilibrium) that makes more moles of gas than it consumes, what is the effect of increasing the pressure?

Suppose the universe were completely empty except for one object-a solid sphere moving through space of 100 km/s. what sort of path would the object be moving in? explain your answer

1) which of the following is the best example of a physical change? a) sugar dissolving in tea b) firefly glowing 2) in the combustion of ethane, what is/are the reactants? c2h6 + o2 ==> co2 + h2o a) c2h6 and o2 b) co2 and c2h6