At 25 degrees Celsius, the concentration of hydronium ions in the blood sample was
a 5.5 x 10-7 M. What is the pH of the blood sample?

d: the voltage of the secondary coil is less than that of the primary coil.

im not suree sorry if wrong

indium, and thallium have three electrons i think

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.  

answer:

technetium is the most reactive. this is followed by silver. the least reactive out of these three elements is strontium.