bks53

27.08.2019 • 

Chemistry

In which of the following conditions would a person not hear an echo?
a. a sound wave reaches the ear,and the reflected wave reaches the ear less than 0.1 seconds later.
b. the reflecting source is approximately 21.5 meters from the person.
c. a person is standing 30 meters in front of the reflecting surface.
d. a person is standing in the range of the sound waves coming from the original sound source as well as the reflected waves.

Ответ:

lilyclairehutson

13.03.2020

Chemistry

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The answer to your question is: +89

Explanation:

Actin has a atomic number of 89, that means that it has 89 protons in its nucleus.

Inside the nucleus are found protons and neutrons, neutrons do not have any charge whereas protons are positively charge, so if we only consider the charge inside the nucleus it will be +89.

It also has 89 electrons that are negatively charged, but they are not in the nucleus.

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