Science Buddies: "Ask an Expert"

Well.. i got the first question on a practice paper wrong.. brilliant i know :/

Table 1 shows some data about fundamental particles in an atom.
Table 1
1 (a) (i) An atom of hydrogen can be represented as 1H
Use data from Table 1 to calculate the mass of this hydrogen atom.

Proton - mass - 1.6725x10^-24
Neutron - mass - 1.6748x10^-24
Electron - mass - 0.0009x10^-24

could you lease tel me how the answer is 1.6734 × 10–24 (g) ?
I'm reallly confused
thanks

Hi!

The first step in solving this problem is to understand that this hydrogen atom has 1 proton, 1 electron, and 0 neutrons. In 1H, it seems that 1 is the mass number. And since the mass number is calculated by adding up the protons and neutrons, and hydrogen always has 1 proton, we can conclude that there are no neutrons. Since there is no positive or negative sign to indicate that this hydrogen atom has lost or gained electrons, we can conclude it is the standard number of electrons for a hydrogen atom, which is 1.

Now, we add up the masses of 1 proton and 1 electron.

(1.6725x10^-24) + (0.0009x10^-24) = 1.6734x10^-24 g

Hope this helps!
-kbannam

Hello Zitalij,

For future reference, this forum is meant to be used asking and answering questions about K-12 science projects. There are other sites for finding help working on homework and tests.

Owen