Answer:
Around 450 B.C.
Explanation:
The idea was forgotten until the 1800 when John Dalton re-introduced the atom.
Answer: from the Zn anode to the Cu cathode
Justification:
1) The reaction given is: Zn(s) + Cu₂⁺ (aq) -> Zn²⁺ (aq) +Cu(s)
2) From that, you can see the Zn(s) is losing electrons, since it is being oxidized (from 0 to 2⁺), while Cu²⁺, is gaining electrons, since it is being reduced (from 2⁺ to 0).
3) Then, you can already tell that electrons go from Zn to Cu.
4) The plate where oxidation occurs is called anode, and the plate where reduction occus is called cathode.
So you get that the electrons flow from the anode (Zn) to the cathode (Cu).
Always oxidation occurs at the anode, and reduction occurs at the cathode.
Answer:
Theories
Explanation:
It is theories because it was a generalistee abstract or thinking generalising the principle of fact about Earth tectonic plates ,it was formulated and concluded as plate tectonic theories after many findings. The theories conclude that the Earth has an outer layer called lithosphere and lies overly a plastic layer called asthenosphere. The lithosphere is divided into several plates and they move close to each other where they diverge, converge or slip over one another.
Density is the measure of a material's mass per unit volume, used in many aspects of science, engineering and industry. Density can be calculated by dividing an object's mass by its volume. Since different materials have different densities, measuring an object's density can help determine which materials are in it. Finding the density of a metal sample can help to determine its purity.When measuring liquids and regularly shaped solids, mass and volume can be discovered by direct measurement and these two measurements can then be used to determine density. Using a pan balance, determine and record the mass of an object in grams. Using a vernier caliper or ruler, measure the length, depth and width of the object in centimeters. Multiply these three measurements to find the volume in cubic centimeters. Divide the object's mass by its volume to determine its density. Density is expressed in grams per cubic centimeter or grams per milliliter.
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