Assuming there is excess acid, the equation for the reaction is Zn + 2HCl -> ZnCl2 + H2.
Mols of zinc = 20/65 (mass/relative atomic mass)
Ratio of Zn : ZnCl2 = 1 : 1
Hence mols of Zinc = mols of Zinc chloride
Mass of ZnCl2 = (20/65)(65+71)
= 41.8g
Answer:
- <em><u>A. isotopes </u></em>
<em><u></u></em>
Explanation:
The <em>periodic table</em> was organized by Dimitry Mendeleiev by 1869, as he showed the connection between the atomic mass and the properties of the elements.
Nevertheless, the order of some few elements had to be altered because the properties did not follow the order of the atomic masses.
Henry Mosely by 1913 determined that atoms of a same element had different number of neutrons, leading to different atomic masses. These atoms of a same element (with the same number of protons) with different number of neutrons are known as<em> isotopes.</em>
By arranging the elements in increasing order of the number or protons (atomic number), instead of the atomic masses, all the elements resulted ordered according with a repetitive (periodic) pattern of chemical properties.
Sound, light, kinetic, heat energy
Answer:
B. NaBr
D. KOH
Explanation:
Below is the solubility rules given for you knowledge.
Salts of
- Group 1 elements are soluble(
) - Ammonium ion is soluble (
) - The nitrate are generally soluble(
- of Cl- , Br- , and I- are soluble, except Ag+ , Pb+2, and (Hg2)+2
- most sulfate are soluble, except Ba+2, Ca+2,Pb+2, Ag+, Sr+2.
- most hydroxide salts are only slightly soluble, except NH+4, Li+, Na+, K+
- Most carbonates are insoluble (CO3 2-) Except group 1 and NH+4
- most phosphate are insoluble except group 1 and NH+4
so using the rules above
NaBr , KOH are soluble, Pb(OH)2 is slightly soluble and AgCl is not soluble.
The sum total<span> of the genetically based </span>variety<span> of </span>living organisms<span> in the </span>biosphere<span> is called a. species diversity. c. biodiversity.</span>
