Mitochondria is the powerhouse of the cell. Only thing I remember from middle school science
A radioactive element is an element which is subject to spontaneous degeneration of its nucleus followed by the emission of alpha, beta and gamma particles. All elements with atomic numbers greater than 83 are radioactive.
The given phrases that describe radioactive elements are-
They have a consistent number of particles
- the particles are alpha, beta and gamma particles.
They have a half-life that determines their rate of decay.
Explanation for other options:
Not all elements occur in nature. Radioactive decay rates may not be constant as the decay happens when a radioactive substance emits a particle. It is not possible to predict exactly when a given atom of a substance will emit a particular particle. When the radioactive element release energy and particles, it decays.
The answer is:
Echinodermata
The word echinodermata is Greek which literally means "Spiny Skin". Echinodermata is a phylum under kingdom animalia. Not all of them have spiny skins, but most of them do. Other characteristics would be their radially symmetric body. They have appendages that grow outward from the center. Examples of echinoderms would be sea stars and sea urchins.
Gases in Earth's Atmosphere. Nitrogen and Oxygen are by far the most common. Dry air is composed of about 78% Nitrogen (N2) and about 21% Oxygen (O2). Argon, Carbon Dioxide (CO2), and many other gases are also present in much lower amounts; each makes up less than 1% of the atmosphere's mixture of gases.
So therefore Oxygen is the gas that makes up the largest portion of the Earths Atmosphere.
Because most waste produced in the cell is toxic when it accumulates.
Hope this helps!
