One kilogram of dry air at STP conditions is exposed to 1.00 R of X-rays. One roentgen is defined by Equation 32.1 in Section 32.1. An equivalent definition can be based on the fact that an exposure of one roentgen deposits 8.30 x 10-3 J of energy per kilogram of dry air. Using the two definitions and assuming that all ions produced are singly charged, determine the average energy (in eV) needed to produce one ion in air.

So I understand that I need to use the equation E=q/m but I don't know how to get it into MeV. Help Please?

To make conversions, go to google, type in "xxjoules to mev" or "xxjolules to electron volts" without the quotation marks and hit the enter button.

in describing an equilibrium reaction involving hydrogen gas, iodine gas, and hydrogen iodide gas, all of the statements about equation Q=[Hl]2 divide [H2][l2]are true except for which one?

Debbie's question isn't complete.

the structural formula,with atoms A,B,and C unspecified,is? [Q2] the formula is C3 H6 Br2 If the compounds is called 1,2-dibromopropane, A,B,and C must be...what?

To determine the average energy (in eV) needed to produce one ion in air, we can use the equation E = q/m, where E is the energy, q is the charge, and m is the mass.

In this case, we need to calculate the energy in MeV, which stands for million electron volts. To convert from joules to electron volts, we can use the conversion factor: 1 eV = 1.602 x 10^-19 J.

We are given that an exposure of one roentgen deposits 8.30 x 10^-3 J of energy per kilogram of dry air. Therefore, we can calculate the energy in joules per ion.

Using the definition in the problem, one roentgen is equal to 8.30 x 10^-3 J/kg. Let's call this Q.

Now, we need to determine the charge (q) associated with one ion in air. Since the problem states that all ions produced are singly charged, the charge q will be equal to the elementary charge, e, which is 1.602 x 10^-19 C.

To calculate the average energy in joules per ion, we multiply the charge (q) by the amount of energy deposited per kilogram of dry air (Q).

E(joules) = q x Q

Now we can convert the energy from joules to MeV. Remember, 1 eV = 1.602 x 10^-19 J.

E(MeV) = E(joules) / (1.602 x 10^-19)

Finally, we can substitute the values into the equation and compute the average energy needed to produce one ion in air.

E(MeV) = (q x Q) / (1.602 x 10^-19)

where q = 1.602 x 10^-19 C (elementary charge) and Q = 8.30 x 10^-3 J/kg (energy deposited per kilogram of dry air).