Answer:
Explanation:
A. The charge on an element is determined by the differences between the number of protons and electrons in an atom.
An atom will have no charges if the number of protons and electrons are the same.
- When an atom loses or gains electrons, the number of electrons will either decrease or increase
- if the number of electrons is more than the number of protons, the excess electrons is the charge on the atom. And this makes the atom become a negatively charged ion.
- if the number of electrons is lesser than the number of protons, the deficient electrons makes the atom a positively charged ion. The number of electrons by which the atom is deficient makes the atom a positively charged ion.
Charge = number of protons - number of electrons
B. Electrons form the charges they do because with the charge, they become stable like the noble gases.
The desire of every atom is to have stable electronic configuration like those of the noble gases.
A potassium atom with a configuration 2 8 8 1 will prefer to lose an electron to become an Argon atom making the ion stable.
The answer is 290.66 mL
Explanation:
The density of any substance including styrofoam is determined by two main factors: mass (atoms in the substance) and volume (space occupied). Moreover, the volume or mass of the substance can be calculated by using the density as these variables are related. Below I show the process:
density = mass / volume
mass = density x volume
volume = mass / density
volume = 21.80 g / 0.075 g/mL
volume = 290.66 mL
Answer:
Sr would be the limiting reactant
5 moles
Explanation:
Since the equation is a balanced equation, the coefficient shows how each substance relates to the other in terms of the number of moles.
Reactants would be those on the left hand side of the arrow, while the products would be found on te right and side of the arrow. In this question, the reactants would be Sr and O₂.
Limiting reactant is the reactant that is insufficient; meaning to say that there is not enough of that substance and thus the reaction cannot continue. The other reactant(s) that is not limiting is called the excess reactants.
From the balanced equation, 2 moles of Sr is needed to react with 1 mole of O₂. Thus, if we have 5 moles of each reactant, Sr would be the limiting reactant since for every 1 mole of O₂, there has to be 2 moles of Sr in order for the reaction to proceed. Thus, if we have 5 moles of O₂, we would need 10 moles of Sr.
When we work out the amount of products formed, we look at the number of moles of the limiting reactant. This is because the limiting reactant determines how much is being reacted, while the excess number of moles of the excess reactant will remain unreacted.
For every 2 moles of Sr reacted, 2 moles of SrO would be produced. This means that the mole ratio of Sr to SrO is 1:1. Thus, since 5 moles of Sr has been reacted, 5 moles of the product (SrO) would be produced.