Explanation:
Reaction equation showing alpha decay in Uranium-238 is as follows.

It is known that an alpha particle is basically a helium nucleus and it contains 2 protons and 2 neutrons.
Symbol of an alpha particle is
.
As atomic mass or weight is the sum of total number of protons and neutrons present in an atom.
Hence, the atomic weight of the alpha particle is (2 + 2) = 4.
In general, solubility increases with temperature. When you increase the temperature of a solvent, you increase the kinetic energy (or energy of movement) of the molecules, and this greater energy helps dissolve more of the solute molecules.
Answer:
When one desires to remove debris from the garden then a soil sifter can be used as a beneficial tool. Based on the needs, it can be of different kinds. A landscaper may sift soil that they use at the time of constructing gardens due to many reasons:
1. The soil becomes aerated, and thus, turn soft and easy to work upon.
2. Sifting the soil makes the work of withdrawing undesired substances from the soil easy.
3. It helps the plants to grow much better as the roots possess the tendency to penetrate more easily through the soil.
4. The soil becomes healthy due to shifting, thus, helps in producing a beautiful and healthy landscape.
i think the answer is B. They have low reactivity.Hope this helped (:
The density of the unknown material is 0.213 ml/g
<h3>
Apparent density of the unknown material</h3>
The apparent density of the unknown material is calculated as follows;
Volume of the unknown substance = 126 ml - 102 ml = 24 ml
Density of the unknown substance = mass/volume
Density of the unknown substance = 24 ml / 112.6 g
Density of the unknown substance = 0.213 ml/g
Thus, the density of the unknown material is 0.213 ml/g
Learn more about density here; brainly.com/question/6838128
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