The mass number represents the summation of the number of protons and the number of neutrons in the nucleus of an atom.
We are given that the mass number is 64 and that the number of neutrons is 35. Therefore:
number of protons = 64 - 35 = 29 protons
In ground state, number of protons in an atom is equal to the number of electrons. Therefore,
number of electrons = 29 electron
Using the periodic table, we will find that the element that has 29 electrons in ground state is copper.
The nuclide symbol of copper is shown in the attached image.
<span>Calculating average atomic mass is exactly like calculating a weighted average. Perform the following calculation:
(mass1)(percentage1) + (mass2)(percentage2) = average atomic mass
(35.0)(0.75) + (37.0)(0.25) = average atomic mass
Make sure your percentages are in decimal form for this calculation.
One of the other answers given is correct, though the explanation is lacking a bit. Two of the answers can be eliminated immediately: 35.0 amu and 37.0 amu cannot be the average. If the mixture of isotopes was 50% and 50%, then 36.0 amu would be correct; however, the mixture is 75/25. This leaves only one possible answer choice.</span>
10 g of glue with 13 g of water ,
Mass ratio of the material can be calculated as:
8 g of sodium borate suspended in 11 g of water, mass ratio can be calculated as:

Answer:
The true statement is option A.
Explanation:
Using ideal gas equation:
PV = nRT
where,
P = Pressure of gas = 1 atm
V = Volume of gas = ?
n = number of moles of gas = 1 mol
R = Gas constant = 0.0821 L.atm/mol.K
T = Temperature of gas = 273.15 K

V = 22.42 L
This means that 1 mole of an ideal gas at STP occupies 22.42 liters of volume.
So, 1 mole of helium gas and 1 mole of oxygen gas will have same value of volume in their respective balloons at STP.