3) Answer is: because elements have different emmision spectrum.
Emission spectrum of a chemical element is the spectrum of frequencies emitted due to an atom making a transition from a high energy state to a lower energy state. Each element's emission spectrum is unique.
4) Answer is: lithium chloride and sodium chloride do not have similar colors.
Lithium ion has red and sodium ion has yellow emission spectrum.
5) Answer is: because metals have valence electrons in different energy shells.
Each transition has a specific energy difference.
6) Answer is: salts of alkaline and earth alkaline metals.
For example barium chloride gives green light.
The rails expand during the heat of a summer day
Is a function defined for a system relating several state variables or state quantities that depends only on the current equilibrium thermodynamic state of the system[1] (e.g. gas, liquid, solid, crystal, or emulsion), not the path which the system took to reach its present state. A state function describes the equilibrium state of a system, thus also describing the type of system. For example, a state function could describe an atom or molecule in a gaseous, liquid, or solid form; a heterogeneous or homogeneous mixture; and the amounts of energy required to create such systems or change them into a different equilibrium state.
Answer:
B
Explanation:
In order for any conduction to take place it needs to go through a solid. Therefore it cannot travel through empty space
