[For Seniors] Lively two-choice trivia quiz. Handy to know and tidbits you'll want to share with others

aluminum foil

The correct answer is “aluminum foil.” Fold the aluminum foil two or three times to add thickness, then snip it several times with scissors. Aluminum is a relatively soft metal, and it’s said that the aluminum melted by the frictional heat while cutting can fill in tiny chips on the blades or act like a whetstone, restoring their sharpness.

blow on it

Disposable heat packs use the heat generated when the iron powder inside reacts with oxygen in the air and oxidizes. Older heat packs needed to be kneaded, but modern ones are designed to warm up just by taking them out of the package, so kneading them too hard can clog the air-intake holes and have the opposite effect. If you want to heat one up quickly, blowing on the pack is effective. The moisture and warmth in your breath accelerate the chemical reaction, allowing the temperature to rise faster than usual.

Warm the lid with hot water

The correct answer is to warm the lid with hot water. This is a practical tip that uses the property of “thermal expansion,” whereby materials expand when heated. Generally, the metal lids used for jam jars are more prone to expansion from heat than the glass jar bodies. Therefore, when you warm the lid with hot water, the metal part expands slightly, loosening the seal and making it easier to open.

ball; sphere; bead; jade; egg; bulb; coin (archaic); gem; orb; testicles (slang)

In the past, the character 玉 was used for tallying numbers, because when written with the correct stroke order it also has five strokes. However, since 玉 can be altered by adding lines to turn it into characters like 王 or 主, there was a risk of falsifying counts. Therefore, from the Meiji era onward, it is said that the character 正, which is harder to alter and also has five strokes, came to be used instead.

rinse

In fact, both rinse (hair conditioner) and fabric softener are made from similar ingredients called cationic surfactants. That’s why dissolving hair conditioner in warm water can reduce static electricity and leave clothes soft and fluffy. It’s a handy emergency substitute technique to remember!

Container design

Surprisingly, many of the ciders and ramune currently on the market have no clear differences in ingredients or flavor. The main distinguishing factor is the container: those sold in the uniquely shaped bottle with a marble are classified as “ramune,” while those in any other type of container are classified as “cider.”

soy sauce

The main reason 10-yen coins become tarnished is rust called copper oxide, which forms when the copper reacts with skin oils and oxygen in the air. Soy sauce contains acidic components that break down and dissolve this copper oxide, restoring the surface’s shine. Other acidic condiments—such as vinegar, lemon juice, Tabasco, and sauce—can produce a similar effect.