My girlfriend and I were having an argument the other day. Sometimes when it is cold in the kitchen, I turn in the gas hob to warm the place up. The argument is that she claims that the room gets hotter if you put a pot of water on the hob to boil and let the room get steamy. I disagree and think that the room gets just as hot without boiling a pot of water.

Who is right? Does the room get hotter with the pot of water or does the room get just as hot without it?

What causes bubbles when boiling water? Is it a gas? If so, where does it come from and why is it only seen when boiling water? Also, when boiling water in a saucepan bubbles suddenly and sometimes violently appear after I move the saucepan or add something like instant noodles. What is happening?

I often fill the kettle from the hot water tap in the hope that perhaps this will save some energy; however, if any of my friends are around whilst I am filling the kettle in this way, I am promptly told that the water from the hot tap is dirty and they certainly do not want tea made with this water. I then argue that the water will be boiled in the kettle, and that the spout of the kettle has a filter, so any nasty things will be killed or filtered out. My friends argue against this. Could I be wrong?

In many parts of England, at least, it is customary to warm the teapot as the initial stage of making a fine cup of tea.  Now that tea made in the mug with a tea bag is pretty universal, am I the only one warming my mug before adding the bag and making the tea, and am I wasting my time?