Answer:
The Aufbau Principle simply helps us determine electron configuration of an atom by stating that in the ground state of an atom or ion, electrons fill subshells of the lowest available energy level, then they fill subshells of higher energy level. For example, the 1s subshell is filled before the 2s subshell is occupied. Now, when trying to figure out the electron configuration of a calcium, you need to know its atomic number to determine its amount of total electrons. Calcium has an atomic number of 20, which means it has 20 protons and 20 electrons. First remember that the "s" subshell only holds 2 electrons, the "p" subshell only hold 6 electrons, and the "d" subshell only holds up to 10 electrons. Using the Aufbau principle below, we can determine that the first two electrons will go in the 1s orbital. Since 1s can only hold two electrons the next 2 electrons go in the 2s orbital. The next six electrons will go in the 2p orbital. The p orbital can hold up to six electrons. We'll put six in the 2p orbital and then put the next two electrons in the 3s. Since the 3s is now full we'll move to the 3p where we'll place the next six electrons. We now go to the 4s orbital where we place the remaining two electrons. With this, the calcium electron configuration will be:

Hope that helps you understand!
The molecules will be more separated, and will have least amount of intermolecular force of attraction.
<h3><u>Explanation:</u></h3>
The molecules inside the jar of Lilly are moving around each other. This means the state of the matter present inside the jar is liquid. As Lily gives more energy inside the jar , the molecules inside the jar will get more separated as the kinetic energy of the molecules increase and the intermolecular force of attraction decreases as well as the intermolecular separation or distance increase. As the energy is continued to be supplied from outside, there will be a time when this liquid will reaches boiling point and will start to change into gas. After this point the intermolecular force of attraction will be least among molecules and their separation will be maximum.
Answer:
Avogadro number of pennies will extend to a distance of 6.02 * 10¹⁷ km
<em>Note: The question is missing some parts. The complete question is as follows;</em>
<em>A penny has a thickness of approximately 1.0 mm . If you stack ed Avogadro's number of pennies one on top of the other on Earth 's surface, how far would the stack extend (in km)? [For comparison, the sun is about 150 million km from Earth and the nearest star (Proxim a Centauri) is about 40 trillion km from Earth.]</em>
Explanation:
Avogadro number = 6.02 * 10²³
thickness of a penny = 1.0 mm
I mm = 0.001 m
Thickness of Avogadro number of pennies stacked one upon another will be:
6.02 * 10²³ * 0.001 m = 6.02 * 10²⁰ m
Distance in km;
1 m = 0.001 km
therefore, 6.02 * 10²⁰ m = 6.02 * 10²⁰ * 0.001 km = 6.02 * 10¹⁷ km
Avogadro number of pennies will extend to a distance of 6.02 * 10¹⁷ km
Answer:
5.2moles of NaCl
Explanation:
The equation for the reaction is:
2Na + Cl2 —> 2NaCl
From the equation,
2moles of Na produced 2moles of NaCl.
Therefore, 5.2moles of Na will also produce 5.2moles of NaCl