The atomic number,atomic mass,valence electrons and the formula for calculating the number of neutrons is also given.The following table has been completed below in the attachment.
Explanation:
Atomic Number:the number of protons /electrons present in the nucleus of an atom is called the atomic number.
Mass Number/Atomic Mass:the number of protons and neutrons present in a nucleus
<u>Example:</u>
;here;6 implies the atomic number and 12 implies the mass number/atomic mass
<u><em>No.of neutrons=Mass number-Number of protons</em></u>
Valence electrons:the number of electrons present in the outer most shell of an atom are called valence electrons
<u>Example:</u>If we consider a carbon atom;as its <em>e</em><em>lectronic configuration is2,4 and</em> it belongs to 4th group.Therefore the number of valency electrons in carbon is <u>4.</u>
The best description for the relationship between the products and the reactants in an exothermic reaction is C. The potential energy of the products is less than the potential energy of the reactants.
I found another question like this. Someone answered "The best answer to this question is adding a catalyst.
Adding a catalyst will cause the greatest increase in the rate of reaction for this chemical reaction , 8Zn(s) + S8(s) 8ZnS(s). ---> adding a catalyst always affects the rate of a reaction."
Air is it gas so it fills its container, the balloon, completely.
Answer:
Percentage lithium by mass in Lithium carbonate sample = 19.0%
Explanation:
Atomic mass of lithium = 7.0 g; atomic mass of Chlorine = 35.5 g; atomic mass of carbon = 12.0 g; atomic mass of oxygen = 16.0 g
Molar mass of lithium chloride, LiCl = 7 + 35.5 = 42.5 g
Percentage by mass of lithium in LiCl = (7/42.5) * 100% = 16.4 % aproximately 16%
Molar mass of lithium carbonate, Li₂CO₃ = 7 * 2 + 12 + 16 * 3 =74.0 g
Percentage by mass of lithium in Li₂CO₃ = (14/74) * 100% = 18.9 % approximately 19%
Mass of Lithium carbonate sample = 2 * 42.5 = 85.0 g
mass of lithium in 85.0 g Li₂CO₃ = 19% * 85.0 g = 16.15 g
Percentage by mass of lithium in 85.0 g Li₂CO₃ = (16.15/85.0) * 100 % = 19.0%
Percentage lithium by mass in Lithium carbonate sample = 19.0%