Answer:
- <u>Tellurium (Te) and iodine (I) are two elements </u><em><u>next to each other that have decreasing atomic masses.</u></em>
Explanation:
The <em>atomic mass</em> of tellurium (Te) is 127.60 g/mol and the atomic mass of iodine (I) is 126.904 g/mol; so, in spite of iodine being to the right of tellurium in the periodic table (because the atomic number of iodine is bigger than the atomic number of tellurium), the atomic mass of iodine is less than the atomic mass of tellurium.
The elements are arranged in increasing order of atomic number in the periodic table.
The atomic number is equal to the number of protons and the mass number is the sum of the protons and neutrons.
The mass number, except for the mass defect, represents the atomic mass of a particular isotope. But the atomic mass of an element is the weighted average of the atomic masses of the different natural isotopes of the element.
Normally, as the atomic number increases, you find that the atomic mass increases, so most of the elements in the periodic table, which as said are arranged in icreasing atomic number order, match with increasing atomic masses. But the relative isotope abundaces of the elements can change that.
It is the case that the most common isotopes of tellurium have atomic masses 128 amu and 130 amu, whilst most common isotopes of iodine have an atomic mass 127 amu. As result, tellurium has an average atomic mass of 127.60 g/mol whilst iodine has an average atomic mass of 126.904 g/mol.
Answer:
Nitrogen, 
Explanation:
Hello,
This is a clear example of what the ideal gas equation is used for, thus, from its mathematical definition:
One can spell it out in terms of mass and molar mass:
Now, solving for the molecular mass, 
:
Now, by taking into account that the gas is diatomic, the matching gas turns out to be nitrogen.
Best regards.
Answer:
OPTION C is correct
C) 1.07 g
Explanation:
CaCl2(aq) + 2 AgNO3(aq) → 2 AgCl(s) + Ca(NO3)3(aq)
But we know molarity molarity= number of moles of solute/ volume of the solution
M= n/V
From the equation above
number of moles of Cacl2 = (37.5 ×0 .100 × 10^-3) = 0.00375 moles.
Then
1 mole of Cacl2 yields 2 moles of Agcl2
0.00375 moles of Cacl2 will produce let say Y.
Y= (0.00375 ×2)/1
= 0.0075 moles.
Number of moles of Agcl2 = mass /molar mass of Agcl
Molar mass of Agcl = 178
Then mass = 178 ×0.0075 = 1.047
Therefore, the mass of agcl precipitate is
1.07 g
Answer:
1.807×10and at the top of ten put -24
Answer:
cyclohexilic acid
Explanation:
The malonic ester synthesis is often used to form different types of carboxilic acid. In this case, we have excess of base, so we can expect a ring formed in the molecule.
In the first step, the base substract the more acidic hydrogen of the ester. In the next step we have the ester reacting with the dibromopentane. Then, in the next step, the excess of base will substract again the acidic hydrogen remaining of the carbon, and then, will promove a Sn2 reaction with the bromine in the pentane (That it was previously attached to the molecule). In this step, a ring id formed. Then, the hydrolisis with acid, will form carboxilic acid in both sides of the molecule, and finally the decarboxilation in heat will separate the molecule and formed the cyclohexilic acid.
The picture below shows the mechanism
