Answer:Answer:
They are inhaled or eaten
Explanation:
Radioactivity can be defined as the process in which an unstable atomic nucleus spontaneously emits ionizing radiation and charge particles. This eventually results in the formation of an energetically stable atomic nucleus.
Examples of radioactive elements are Uranium, Polonium, Thorium, Radon, etc. The radiation emitted during this process is classified as;
1. Alpha radiation (α).
2. Beta radiation (β).
3. Gamma radiation (G).
Alpha-emitting substances, such as radon gas, can be a serious health hazard only if they are inhaled or eaten. Alpha-emitting substances compared to other radiation has very short-range particle and as such cannot penetrate the human skin or body.
Answer:
Frequency = 24 × 10⁸ Hz
Explanation:
Given the following data;
Speed = 3 × 10⁸ m/s
Wavelength = 0.125 meters
To find the frequency of the electromagnetic wave;
Mathematically, the speed of a wave is given by the formula;
Speed = Wavelength × frequency
Substituting into the formula, we have;
3 × 10⁸ = 0.125 × frequency
Frequency = (3 × 10⁸)/0.125
Frequency = 24 × 10⁸ Hz
Doppler Effect is required to solve the problem. The Doppler effect is the change in the perceived frequency of any wave movement when the emitter, or focus of waves, and the receiver, or observer, move relative to each other. The general formula of observed frequency, due to Doppler's effect is as follows,

= Frequency observed by observer
v = Velocity of Sound
= Velocity of observer
= Velocity of source
= Frequency of source
PART A) Replacing our values we have that,



PART B) Here the same procedure is performed but this time repeated in the opposite direction.



Mass is a property of an object, a cloud of gas, a puddle of liquid, or a lump of goo, and doesn't necessarily change when the object moves to a different location or environment. It depends only on the object itself.
Weight is completely a product of what else is in the nearby location,so it can easily change. It's the result of the gravitational forces between <em>two</em> objects . . . the first one with the constant mass, and <em>another one</em> that also has mass. The forces between them, and therefore the weight, depend on <u>both</u> masses, AND on the distance between them.
C)Weight
A)An attraction between two objects that have mass
B)Force decreases as distance increases.
grav force of massive planet increases your weight