Answer:
The highly unstable pure sodium or potassium wants to lose an electron and this splits the water atom, producing a negatively charged hydroxide ion and hydrogen and forming an explosive gas that ignites.
Explanation:
Answer:

Explanation:
Given that,
Mass of the sample, m = 275 g
It required 10.75 kJ of heat to change its temperature from 21.2 °C to its melting temperature, 327.5 °C.
We need to find the specific heat of the metal. The heat required by a metal sample is given by :

c is specific heat of the metal

So, the specific heat of metal is
.
Combustion means the burning of something. So in the given question, you could say, “In this question, combustion means the burning of methane”.
It is a element.
Pure substances includes either compunds, or elements. Elements are the simplest form of pure substance, they only consist of one kind of atoms. On the other hand, compounds contains two or more elements that are chemically combined together. Although you couldn't separate a compound by physical methods like filtration, but you can seperate them with chemical methods such as heating or electrolysis, using electricity.
Therefore, since compounds can be broken down eventually, so, the answer will be element.