…Sparklers sparkle 
The sparkles in sparklers are the sparks of burning metal particles, usually aluminium, but can also be of iron, titanium, zinc or magnesium. As they burn, the little metal particles undergo a reaction with oxygen to form metal oxides. Sparklers also contain potassium perchlorate, a substance that produces oxygen when it burns. This oxygen is used up by the metal particles so they can burn. The sparkler’s sparks do not travel far, since the metal particles are very small and burn up quickly.  

…Sugar tastes good to us 
Sugar is a source of calories or energy. In ancient times, the humans who ate the most calories had a better chance of surviving and thus passing on their genes to their children. Fruits are the most common, natural source of sugar. They provide more energy than other foods, even vegetables. But they were scarce and not easily available in prehistoric times. Some scientists therefore conclude that the early humans who ate the most fruits lived longer and had more babies. Those babies, in turn, may have inherited a craving for sugary fruits from their parents, as this was part of their survival. This trait would’ve been passed on to future generations subsequently, which is why sugar tastes good to us too.

…New clothes feel stiff 
New clothes are treated with several chemicals before they are sold. These chemicals prevent wrinkles, repel stains, enhance softness, and ensure the colours stick to the garments. Among these chemicals is formaldehyde, which prevents wrinkles and enhances the texture of certain fabrics. Formaldehyde is toxic to humans, but usually, clothes contain a small amount, within the limit set by laws and governments. However, these chemicals can irritate people with sensitive skin. Therefore, if you are someone with such skin or would like to avoid the chemicals, you can wash your new clothes before you first wear them.