Answer:
Stirring the salt and water
Crushing the salt so the grains are smaller
Explanation:
Another way that is not in the choices that would increase the rate of dissolving of a solute in the solvent is heating the solvent. This increases the kinetic energy of the particles hence increasing collision rates. This helps increase the dissolution of the solute.
Stirring helps break down the solute to smaller particles. Smaller particles have a larger surface area to volume ration on which collision with solvent molecule can occur hence faster dissolution.
Answer: Na
Explanation:
The sodium on the left is elemental sodium, the oxidation state is zero. The sodium on the right of the equation is the sodium ion, which is +1. The oxidation number has increased from zero to +1, which is oxidation. (Oxidation is the loss of electrons leading to a more positive oxidation state.
Answer: The ratio of atoms in calcium bicarbonate ; Ca : H : C : O = 1:2:2:6.
The ratio of atoms in lithium sulfide; Li : S = 2 : 1
Explanation:
In calcium bicarbonate:
In a molecular formula of calcium carbonate there are:
Number of Calcium atoms = 1
Number of Hydrogen atom = 1 × 2 = 2
Number of Carbon atoms = 1 × 2 = 2
Number of Oxygen atoms = 3 × 2 = 6
So, Ca : H : C : O = 1 : 2 : 2 : 6
In lithium sulfide :
In a molecular formula of lithium sulfide there are:
Number of Lithium atoms = 1 × 2 = 2
Number of Sulfur atoms = 1
So, the Li : S = 2 : 1
Answer:
A. in which oxidation numbers change
Explanation:
This is because in oxidation reduction reactions or redox reactions, involves the sharing or transfer of electrons between species and the oxidation numbers changes. There is change in electrons, ions or oxidation number by gaining or lossing electrons. Increase in oxidation number is an indication of oxidation while decrease in oxidation indicate reduction.
The results of this experiment gave Rutherford the means to arrive at two conclusions: one<span>, an atom was much more than just empty space and scattered electrons and </span>two<span>, an atom must have a positively charged center that contains most of its mass (which Rutherford termed as the </span>nucleus<span>).
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