Answer: C and D
Explanation:
B is talking about cells, so it's not relevant
A has nothing to do with this at all honestly
So C and D are the right answers
Answer:
The correct answers are A, B and D. The Clean Air Act was important because it emphasized cost-effective methods to protect the air; encouraged people to study the effects of dirty air on human health; and created a regulation that makes any activities that pollute the air illegal.
Explanation:
The Clean Air Act is a federal federal law designed to control air pollution nationwide. The Environmental Protection Agency (EPA) is required to develop and enforce the regulations to protect the general public from exposure to air pollutants that are known to be dangerous to human health. The 1963 law established a basic research program, which was expanded in 1967. The main changes to the law, which require regulatory controls of air pollution, were promulgated in 1970, 1977 and 1990.
The 1970 amendments significantly expanded the federal mandate by demanding broad federal and state regulations, both for fixed sources of pollution (industrial) and mobile sources.
In 1990 provisions were added to deal with acid rain, depletion of the ozone layer and toxic air pollution, and a program of national permits of fixed sources was established. Also new requirements were established for the reformulation of gasoline, the adjustment of Reid vapor pressure (RVP), which measures the volatility of gasoline; and the norms to control the evaporation emissions of the gasoline.
The Clean Air Act is important because it was the first important environmental law in the United States to include a disposition regarding citizen demands. Numerous local and state governments have promulgated similar laws, either the execution of federal programs or to fill important loopholes at the local level in federal programs.
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.
Answer:
C
Explanation:
Every living thing is made up from cells, as they are the smallest unit of a living thing.
