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worty [1.4K]
3 years ago
6

Which of the following describes a study that is “longitudinal”?

Chemistry
1 answer:
jolli1 [7]3 years ago
7 0

Answer:

A longitudinal study is a observational study that follows the same subjects repeatedly over a period of time, in some cases from birth to death

or

the same adults are tested at each time point: 20, 30, and 40 years of age

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Why might an idea or hypothesis be discarded? A. If another scientist doesn't like it. B. If evidence also supports another hypo
vladimir1956 [14]

Answer:

C. If it is tested and the evidence does not support it.

Explanation:

A hypothesis is more less a scientific guess. Before such a guess or prediction is made, empirical observations and deductions are first made. It is from the result of the observations that a hypothesis statement is made.

For a hypothesis to become widely adopted and accepted, it must be testable within the limits of the experiment as described by the proposer. When subjected to test and it agrees, the status of a hypothesis can be upgraded.

If the hypothesis is tested and evidence contrasts the result being sort for, a hypothesis will be discarded.

7 0
3 years ago
When considering light moving through a diffraction grating, you should treat the light as what?
liraira [26]

Answer:

A particle

Explanation:

Modern quantum theory holds that light has both wave-like and particle-like properties. When the length scales involved are large compared to the wavelengths of light (ex., forming images with thin lenses), the

particle nature of light dominates.

5 0
3 years ago
Read 2 more answers
A first-order reaction is 81omplete in 264s. A. What is the half-life for this reaction? b. How long will it take for the reacti
Arlecino [84]

A first-order reaction is 81omplete in 264s.The half-life for this reaction (i) t 1/2 = =3.465×10 −3 s.to reach 95% Completion = 285 s.

To measure reaction rates, chemists initiate the reaction, measure the concentration of the reactant or product at different times as the reaction progresses,

For a 0-order response, the mathematical expression that may be employed to determine the half of life is: t1/2 = [R]0/2k. For a first-order reaction, the half of-existence is given by: t1/2 = zero.693/ok. For a 2d-order response, the method for the half-life of the response is: 1/okay[R]0

The 1/2-life of a response (t1/2), is the quantity of time needed for a reactant concentration to lower via half of compared to its initial awareness. Its software is used in chemistry and medicine to are expecting the awareness of a substance over time

Half of the lifestyles is the time required for exactly 1/2 of the entities to decay   50%.

Learn more about first order reaction here:-

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5 0
2 years ago
Why do we sometimes use roman numerals in naming ionic compounds?
Blababa [14]
Roman numerals are used in naming ionic compounds when the metal cation forms more than one ion. The metals that form more than one ion are the transition metals, although not all of them do this.
6 0
3 years ago
Read 2 more answers
PLS ANSWER ALL QUESTIONS FOR 67 POINTS
Elena L [17]

Explanation:

1. subatomic particles. 

2.proton, electron and neutron

3.The atomic mass of an element is actually the sum of the MASSES of protons and neutrons in AN atom of that element

4.An element's atomic number is equal to the number of protons in the nuclei of any of its atoms

5. Number of Protons = Atomic Number

Number of Electrons = Number of Protons = Atomic Number

Number of Neutrons = Mass Number - Atomic Number

For krypton:

Number of Protons = Atomic Number = 36

Number of Electrons = Number of Protons = Atomic Number = 36

Number of Neutrons = Mass Number - Atomic Number = 84 - 36 = 48

6. electron, lightest stable subatomic particle known. It carries a negative charge of 1.602176634 × 10−19 coulomb, which is considered the basic unit of electric charge. The rest mass of the electron is 9.1093837015 × 10−31 kg

7.The center of the atom is called a nucleus

8. Negatively charged particles are found in multiple layers outside the nucleus of the atom. These particles are called electrons, and they orbit in various energy levels around the atom's nucleus.

9. A charged particle is also called an ion

3 0
3 years ago
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