Yes, everything takes up space.
Cubes
No. Water expands when it freezes so when it melts, it will take up a smaller volume.
Approximately 16-18 ice cubes make up one cup of crushed ice, while for larger cubes, it may take 8-10 to make up a cup. The actual number can vary based on the size of the ice cubes and how they are packed.
A person would be able to purchase light up ice cubes at walmart, amazon, or many of the major retail companies in the world. A popular brand is "Lited Ice Cubes"
because water heats up faster
Yes. Salt, for example, will speed up the melting of ice cubes.
a ice cube melts when it heats up
You can use ice cubes and a silk handkerchief for a simple magic trick. By placing the ice cubes in the handkerchief and then tying it up, you can create the illusion of making the ice disappear as it melts. Additionally, you can use the handkerchief to keep drinks cool by wrapping ice cubes in it and placing it in a beverage container.
Ice cubes melt faster in the sun because sunlight is a form of radiant energy that warms the ice cubes, causing them to absorb heat and melt more quickly. The higher temperature from the sun speeds up the rate of melting compared to ice cubes kept in the shade.
Ice does float, but if you put in multiple ice cubes, the ice cubes underneath can't push up over and on top, so it looks like they're floating in the middle of the glass.
4 ounces of water will take up more space than 4 ounces of ice, as water is a liquid and ice is a solid. When water freezes into ice, it expands, increasing its volume.
Ice cubes explode in a drink because they are melting at a fast rate. The ice cannot contract fast enough to keep up with the melting, which causes it to crack.