The majority of an atoms' mass comes from the protons and neutrons that make up its nucleus.
The answer is B.) benzaldehyde sorry if I’m wrong
Answer:
Explanation:
Use Dalton's law and the vapor pressure of water at 23.0 o C to correct the pressure to units of atmoshperes.
PT = Poxygen +Pwater
At 23.0 o C the vapor pressure of water is 21.1 mmHg. (This can be found on a vapor pressure table.)
762 mmHg = Poxygen + 21.1 mmHg
Poxygen = 762 mmHg - 21.1 mmHg
Poxygen =741 mmHg
Convert the corrected pressure to atmospheres.
(741 mmHg) (1 atm / 760 mmHg) = 0.975 atm
Use the ideal gas law to find out how many moles of gas were produced:
PV = nRT (remember to put volume in liters and temperature in Kelvin)
(0.975 atm) (.193 L) = n (.0821 L atm / mol K) (298 K)
n = (0.975 atm) (.193 L) / (.0821 L atm / mol K) (298 K)
n = 7.69 X 10-4 mol
Use the number of moles and the molecular weight of oxygen to find out how many grams of oxygen were collected.
(7.69 X 10-4 mol) (32.0 g / 1 mol) = 2.46 X 10-2 g
Answer:
70.1 mL
Explanation:
First let's look at the formula for magnesium nitrate, and get the molar mass, we should end up with Mg(NO3)2 for the formula and this should have a molar mass of 148.3 g/mol.
Lets get the number of moles of the magnesium by taking the number of grams over the molar mass, (21.94 g)/(148.3 g/mol). grams cancel and we're left with approximately 0.148 moles.
Now let's plug our numbers into the molarity formula, M = n/L, this should give us 2.11 mol/L = (0.148 mol)/L, now let's solve for L, divide both sides by 0.148 which will give us 14.26 L^-1 = 1/L now we take the inverse of both sides to get 0.07012 L = L.
Now we have the liters, but the question askes for milliliters, so let's multiply by 1000, and then after rounding to sig figs we will get 70.1 mL as our answer. (Note: I used the exact values instead of the approximations throughout this explanation, so if you calculate the answer by plugging in these values, it might be slightly off.)
Atoms are made of three types of sub atomic particles, they are the electrons, neutrons and protons.
Electrons are negatively charged and they are orbiting around the nucleus in energy shells. Protons are positively charged , neutrons are neutral and have no charge, both neutrons and protons are located in the nucleus.
In atoms the atomic number is the number of protons the atom consists of and mass number is the sum of protons and neutrons in the nucleus.
In a neutral atom, the number of electrons and protons are equal, this means that the number of negative charges and positive charges are equal.
lets take Cl as an example. Its atomic number is 17.
number of protons and charge - +17
number of electrons with charge - -17
overall chage sum of the charges = + 17 -17 = 0
therefore no charge, hence its neutral.
isotopes are the same element having the same atomic number but different mass numbers.
³⁵Cl -protons - 17 electrons - 17 neutrons 18 neutrons
³⁷Cl - protons - 17 electrons - 17 neutrons 20 neutrons
Both are same element with same number of protons and electrons, however the number of neutrons are different.
Since protons + neutrons = mass of the atom
and when the number of neutrons change - mass of atoms too change
hence, ³⁵Cl has a mass of 35 and ³⁷Cl has a mass of 37. both of these are called isotopes
Ions are atoms which have either gained an electron or lost an electron and are charged.
metals such as K(atomic number - 19) have one valence electron in the outer shell, to gain the configuration of a complete octet, K needs to give out this one electron.
then number of electrons 19-1 = -18
number of protons = +19
overall charge = +1
K is one electron less therefore becomes positively charged and called a cation- K⁺
if we take Cl, atomic number - 17
Cl has 7 valence electrons, to gain a complete octet in the outer shell it needs to have 8 electrons, therefore it needs one more electron to complete the outer shell.
Therefore it gains one electron,
number of electrons 17+1 = -18
number of protons = 17
overall charge = -1
with an extra electron, Cl becomes negatively charged, a negative ion called anion - Cl⁻
