Answer: The correct option is 4.
Explanation: All the options will undergo some type of radioactive decay processes. There are 3 decay processes:
1) Alpha decay: It is a decay process in which alpha particle is released which has has a mass number of 4 and a charge of +2.
2) Beta-minus decay: It is a decay in which a beta particle is released. The beta particle released has a mass number of 0 and a charge of (-1).
3) Beta-plus decay: It is a decay process in which a positron is released. The positron released has a mass number of 0 and has a charge of +1.
For the given options:
Option 1: This nuclei will undergo beta-plus decay process to form 
Option 2: This nuclei will undergo beta-minus decay process to form 
Option 3: This nuclei will undergo a beta minus decay process to form 
Option 4: This nuclei will undergo an alpha decay process to form 
Hence, the correct option is 4.
86 percent is the percent yield for this experiment if he expected to produce 5g of product.
Explanation:
Given that:
mass of test tube = 5 grams
mass of test tube + reactant is 12.5 grams
mass of reactant = ( mass of test tube + reactant ) - (mass of test tube)
mass of reactant = 12.5 -5
= 7.5 grams
when 7.5 grams of reactant is heated mass of test tube was found to be 9.3 grams.
so mass of product formed = 9.3 - 5
= 4. 3 grams of product is formed (actual yield)
However, he expected the product to be 5 grams (theoretical yield)
Percent yield = 
x 100
putting the values in the formula:
percent yield = 
x 100
= 86 %
86 percent is the percent yield.
Answer: Option (D)
Explanation: Chemical weathering refers to the breakdown of minerals and forming new minerals due to the presence of chemical elements. For example, hydrolysis.
Due to the chemical weathering, initially, the minerals will get dissolved and are carried to the streams and oceans. After that, due to the saturation by water, the crystals will be precipitated out of that existing solution.
This crystals then sinks down to the bottom, forming sedimentary rocks.
Thus, the correct answer is option (D).
Enzymes affect the rate of the reaction in both the forward and reverse directions; the reaction proceeds faster because less energy is required for molecules to react when they collide. Thus, the rate constant (k) increases. Figure 3: Lowering the Activation Energy of a Reaction by a Catalyst.
hope this helps!
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Answer:
A. Their numbers of atoms
Explanation:
