Answer is: nickel (Ni) is the most active metal.
Chemical reaction 1: Pb(NO₃)₂(aq) + Ni(s) → Ni(NO₃)₂(aq) + Pb(s).
Chemical reaction 2: Pb(NO₃)₂(aq) + Ag(s) → no reaction.
Chemical reaction 3: Cu(NO₃)₂(aq)) + Ni(s) → Ni(NO₃)₂(aq) + Cu(s).
From chemical reactions 1 and 3, we can conclude that nickel is more reactive than lead (Pb) and copper (Cu), because lead is more reactive than silver (Ag), chemical reaction 2, nickel is also more reactive than silver.
In chemical reaction 2, no reaction occurs because silver is less reactive than lead. Lead is higher in activity series of metals and can not be reduced.
Nickel is higher in activity series of metals than lead, copper and silver.
The activity series is a series of metals from highest to lowest reactivity. Metal higher in the reactivity series will displace another.
Answer:
Paper
Explanation:
In chromatographic separation, two different phases are important; a stationary phase and a mobile phase.
The stationary phase is the phase that does not move. Substances are separated based on how fast or slowly they move in the stationary phase.
The mobile phase is usually the solvent(or mixture of solvents) that carries the solutes through the stationary phase.
The stationary phase is usually composed of a porous material. Paper is a porous material. The mobile phase is trapped between the cellulose fibers of the paper and separation is achieved.
A variable, which is controlled or changed in a scientific experiment to examine the influences on the dependent variable is known as an independent variable. On the other hand, a dependent variable refers to the variable, which is being measured and tested in a scientific experiment.
In the given case, one is observing that how the amount of salt in a mouse food influences the water the mouse drinks. Thus, the amount of salt in the food in the given case is an independent variable, as one can determine the amount of water consumed by the mouse, by manipulating the amount of salt intake given to the mouse.
Hence, the correct answer is option B.
Answer:
The modern understanding of an atom was developed by the quantum theory
