Answer:
Charge is caused by a flow of electrons, since electrons are around the nucleus they can be lost or gained by atoms. When an atom gets charged, it gains a charge, that is, it gains an electron. Since electrons are negatively charged, when an atom gains one, it also becomes negatively charged.
The question is incomplete, the complete question is:
Standardization of a Borax solution (Na2B4O7). A student titrates a 20.00 mL sample of an aqueous borax solution with 1.044 M H2SO4. It takes 2.63 mL of acid to reach the equivalence point. Knowing it takes 1 H2SO4 to neutralize 2 Na2B4O7, what was the concentration of this Borax solution?
<u>Answer: </u>The concentration of borax solution is 0.069 M.
<u>Explanation:</u>
To calculate the concentration of borax solution, the formula used is:
....(1)
where,
are the n-factor, concentration and volume of sulfuric acid
are the n-factor, concentration and volume of borax solution.
We are given:
Putting values in equation 1, we get:
Hence, the concentration of borax solution is 0.069 M.
Answer:
(a) Alkali metals: Francium (Fr)
(b) Chalcogens: Polonium (Po)
(c) Noble gases: Radon (Rn)
(d) Alkaline earth metals: Radium (Ra)
Explanation:
In the periodic table, the atomic mass increases down the group. Therefore, the last element of a group is the heaviest element of the group.
(a) alkali metals: The chemical elements that are present in group 1 of the periodic table, except hydrogen.
<u>The heaviest member of this group is francium (Fr)</u>
(b) chalcogens: The chemical elements that are present in group 16 of the periodic table
<u>The heaviest member of this group is polonium (Po)</u>
(c) noble gases: The chemical elements that are present in group 18 of the periodic table
<u>The heaviest member of this group is radon (Rn)</u>
(d) alkaline earth metals: The chemical elements that are present in group 2 of the periodic table.
<u>The heaviest member of this group is radium (Ra)</u>
Rock
Density Range Minerals React
(g/mL) with Acid?
granite 2.5-2.8
no
dolomite 2.8-2.9
yes
peridotite 3.1-3.4
no
limestone 2.3-2.7
yes
iron ore
4.5-5.3
no
Based on the information in the table and Nguyen's data, rock X is correctly identified as
rock Y is correctly identified as
and rock Z is correctly
The answers in the other two boxes are Dolomite, Granite, and Limestone