Answer:
Helium
Explanation:
Atomic radii vary in a predictable manner across the periodic table. As can be seen in the figures below, the atomic radius increases from top to bottom in a group and decreases from left to right over a period of time. Helium is therefore the smallest element, and francium is the largest.
Radioactive decay is the loss of energy by unstable atomic nuclei. The reaction shows alpha decay. Thus, option d is correct.
<h3>What is alpha decay?</h3>
Alpha decay is a type of radioactive decay in which an alpha particle or the helium ion is released from the parent cell to produce the daughter nucleus.
The alpha decay in the isotope of the uranium to thorium and an alpha particle is shown as:
²³⁵U₉₂ → ²³¹Th₉₀ + ⁴He₂
In beta decay, a negatively charged electron is emitted along with the daughter nucleus and in gamma decay, gamma rays without charge and mass are emitted.
Therefore, the reaction shows option d. alpha decay.
Learn more about alpha decay here:
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Hello,
Work is done when a force causes an object to move in the same direction that the force is applied..... Friction reduces efficiency because when two surfaces slide past each other, friction resists their motion, and in real machines, some input work is always used to overcome friction.
Hope this helps!!!! Happy Holidays!!!! (:
Answer:
Distillation can be used to soften water as the water evaporates as it is heated and the ions are left behind.
Hope that helps. x
