Match the description to the property.
frequency
distance between a crest and a crest
or a trough and a trough
amplitude
the distance traveled per unit of time
period
the amount of time it takes for a
wavelength to pass a certain point
speed
distance between the midpoint to a
crest or the midpoint to a trough
wavelength
number of wavelengths that pass a
fixed point in a second

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.  

idk what is it? is this a question that you know the answer or u dont

im doing test rn im going with 2 but ill give answer if itss wrong,   : )