Shielding electrons are the electrons in the energy levels between the nucleus and the valence electrons. They are called "shielding" electrons because they "shield" the valence electrons from the force of attraction exerted by the positive charge in the nucleus. Hope this helps!!
Cardenolides, with the chemical formula CH₁₈C₂₀H₁₅CHCO₂ have (D) 23 carbon atoms, 34 hydrogen atoms, and 2 oxygen atoms.
Milkweed contains a poison known as cardenolides. The chemical formula for cardenolides CH₁₈C₂₀H₁₅CHCO₂.
The subscripts in the formula represent the atomicities, that is the number of atoms of each element in each part of the formula.
We can calculate the total number of atoms of each element by adding its atomicities.
<h3>Carbon atoms</h3>

<h3>Hydrogen atoms</h3>

<h3>Oxygen atoms</h3>

Cardenolides, with the chemical formula CH₁₈C₂₀H₁₅CHCO₂ have (D) 23 carbon atoms, 34 hydrogen atoms, and 2 oxygen atoms
Learn more: brainly.com/question/13348838
There are several differences between<span> a </span>physical and chemical change<span> in matter or substances. A </span>physical change<span> in a substance doesn't </span>change<span> what the substance is. In a </span>chemical change<span> where there is a </span>chemical<span> reaction, a new substance is formed and energy is either given off or absorbed.</span>
I cannot fully remember but the charge of a compound always has to be the same. However, I believe that the sign of the Y2 means that it is positive 2.
so in my opinion it is in between b and c. use your best judgment.
<span>6.38x10^-2 moles
First, let's determine how many moles of gas particles are in the two-liter container. The molar volume for 1 mole at 25C and 1 atmosphere is 24.465 liters/mole. So
2 L / 24.465 L/mol = 0.081749438 mol
Now air doesn't just consist of nitrogen. It also has oxygen, carbon dioxide, argon, water vapor, etc. and the total number of moles includes all of those other gasses. So let's multiply by the percentage of nitrogen in the atmosphere which is 78%
0.081749438 mol * 0.78 = 0.063764562 mol.
Rounding to 3 significant figures gives 6.38x10^-2 moles</span>