Answer:
A, C, and D
Explanation:
The correct options that apply to the principal conservation of energy are A, C, and D.
A is correct because energy can neither be created nor destroyed. However, energy can be transfered from one location to another or be converted from one form to another. <em>Whether transferred to converted, the magnitude remains the same.</em>
C is correct because energy cannot be destroyed but can be transferred or converted. <em>Hence, if a body or a location loses temprature, then the loss is being gained by another body or location.</em>
D is also correct. A closed system is a system that does not exchange matter with its surroundings. <em>Hence, the total energy remains the same within the system. </em>
<u>Answer:</u> The number of valence electron in the given atom are 5
<u>Explanation:</u>
Valence electrons are defined as the electrons which are present in the outermost shell of an atom. Outermost shell has the highest value of 'n' that is principal quantum number.
For the given electronic configuration: 
When an element belongs to d-block, the number of valence electrons are present in 
orbitals
Here, n = 4
The electrons in '4s' orbital = 2
The electrons in '3d' orbital = 3
Number of valence electrons = 2 + 3 = 5
Hence, the number of valence electron in the given atom are 5
The phosphate ion has a formula of PO₄⁻³
It is visible that there is one phosphorus atom and four oxygen atoms. Moreover, we know that both phosphorus and oxygen are non-metallic elements, so the bonding that must be present between them is covalent bonding.
Finally, the charge of an ion is distributed over the entire ion so that it is stabilized. Thus, the answer is:
<span>It is composed of one phosphorus atom and four oxygen atoms covalently bonded together, and there is a –3 charge distributed over the entire ion</span>
1.679 × 10²³ g of PbO₂ is present in 4.23×10⁴⁴ particles of PbO₂.
<u>Explanation:</u>
First the number of particles is converted into moles by dividing it by the Avogadro's number and then moles multiplied by the molar mass, we will get the mass of PbO₂ in grams.
4.23×10⁴⁴/ 6.022×10²³ = 7.02×10²⁰ moles
Now we have to multiply this by the molar mass of PbO₂, that is 239.2 g/mol, we will get the mass in grams.
7.02×10²⁰ moles × 239.2 g/mol = 1.679 × 10²³ g of PbO₂
Answer:
"One mole of any gas has a volume of 24 dm3 or 24,000 cm3 at rtp (room temperature and pressure). This volume is called the molar volume of a gas."
Explanation:
Divide the mass of neon.
