Isotopes with unstable nuclei are_______and are called _______.
1 answer:
You might be interested in
Answer:
B. electrons possess the largest charge-to-mass ratio among the subatomic particles listed in the four choices.
Explanation:
Consider the mass of each particle. Express the masses in atomic mass units:
- Protons: approximately 1.007 amu each;
- Neutrons: approximately 1.009 amu each;
- Electrons: approximately 0.0005 amu each.
Similarly, consider the charge on each particle. Express the charges in multiples of the fundamental charge:
- Protons: +1 e;
- Neutrons: 0;
- Electrons: -1 e.
Calculate the charge-to-mass ratio for the three species:
- Protons: approximately
;
- Neutrons: 0;
- Electrons: approximately
.
Almost all nuclei contain protons and neutrons. The only exception is the hydrogen-1 nucleus, which contains only one proton and no neutron. The mass of the nucleus is approximately the same as the sum of its components' masses. The extra neutron will only add to the mass of the nucleus (the denominator) without contributing to the charge (the numerator.) As a result, the charge-to-mass ratio of nuclei will be positive but no greater than the charge-to-mass ratio of protons.
Among the particles in the four choices, the charge-to-mass ratio is the greatest for electrons.
<h3>Answer:</h3>
250.756 moles He
<h3>Explanation:</h3>From the question we are given;
Volume, L = 685 L
Temperature, T = 621 K
Pressure, P = 189 × 10 kPa
We are required to calculate the number of moles of the gas,
Using the Ideal gas equation,
PV = nRT, where P is the pressure, V is the volume, T is the temperature, n is the number of moles, and R is the ideal gas constant.
We can replace the known variables and constant in the equation to get the unknown variable, n.
Using ideal gas constant as 8.3145 L.kPa/K/mol
n = 250.756 moles
The moles of helium contained in the sphere is 250.756 moles