Distance
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Miles
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1pm
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A cyclist was training for a race and completed a ride on
Saturday morning. Her ride is represented by the graph;
using the graph, determine the cyclist's average speed.

it's c. elements are placed in rows based on how may valencies electrons have.

space exploration has led to the development and technological improvement of many everyday items. (if this answer is wrong i will find the right answer) : )

explanation:

let the different atoms be x and y. each with four protons and same mass will be represented as follows.

mass number is number of protons + number of neutrons.

            and  

since, it is given that one has a negative charge while the other is neutral. therefore, there will be increase in number of protons and the atom will be represented as follows.

according to periodic table, mass number of beryllium is 9 and it has atomic number 4 so, the atoms will be and .  

the protons and neutrons will be located inside the nucleus whereas the electrons will be revolving around the nucleus.