Are alkali or alkaline earth metals more reactive?
The alkali metals are more reactive than alkaline earth metals as alkali metals have just one valence electron and this makes atom more reactive. This makes alkaline earth metals less reactive as they have two valence electrons.
Are the more active alkali metals at the top or the bottom of the group?
The reactivity of alkali metals increases from the top to the bottom of the group, so lithium (Li) is the least reactive alkali metal and francium (Fr) is the most reactive. Because alkali metals are so reactive, they are found in nature only in combination with other elements.
Do the alkali metals have high or low density?
The alkali metals also have low densities . They are low enough for the first three (lithium, sodium and potassium) to float on water.
Do alkali metals have a high melting point?
The alkali metals have low melting points, ranging from a high of 179 °C (354 °F) for lithium to a low of 28.5 °C (83.3 °F) for cesium. Alloys of alkali metals exist that melt as low as −78 °C (−109 °F). The alkali metals react readily with atmospheric oxygen and water vapour.
Which of the following alkali metal is having least melting point?
What can you use to melt metal?
Types of Metal Casting Metals can be melted using a torch, an electric, propane, induction furnace, or even a microwave melting furnace.
What do you pour molten metal into?
In a foundry, molten metal is poured into molds. Pouring can be accomplished with gravity, or it may be assisted with a vacuum or pressurized gas. Many modern foundries use robots or automatic pouring machines to pour molten metal.
Can hot metal start a fire?
Hot metal fragments can be created from power lines, overheated brakes, railway tracks or any other manner of metal-on-metal action in our industrialized society. At least 28,000 fires occur each year in the United States due to hot metal hazards, according to a 2013 U.S. Department of Agriculture report.
What can not catch on fire?
Fire-retardant materials used in buildings
- Mineral wool.
- Gypsum boards.
- Asbestos cement.
- Perlite boards.
- Calcium silicate.
- Sodium silicate.
- Potassium silicate.
What Cannot be burned by fire and won’t drown in water?
The right answer to the riddle is Ice. Ice melts instead of burning in a fire and it floats in water. Now if you take a look at the riddle, you can see, that the ice can’t be burned in a fire nor drowned in water.