Answer:
I think it's 6 but I'm not quite sure
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: because the phospholipid bilayer formed by these interactions makes a good barrier between the interior and exterior of the cell, because water and other polar or charged substances cannot easily cross the hydrophobic core of the membrane.
Explanation:
Answer:
TRUE
Explanation:
Main job of calorimeter is to measure energy changes or determine specific heat capacity of different substances. Specific heat is an intensive property (like density, color, etc.) that does not depend on the amount of a substance present. This allows substances to be identified using their specific heat. Thus, calorimeter comes very handy in determining the specfic heat of unknown substance.
Answer:
Sulfate = tetrahedral
Explanation:
N° Geometry Formula
2 linear AX2
3 trigonal-planar AX3 or AX2E
4 tetrahedral AX4/AX3E/AX2E2
a) Nitrate = NO3-
⇒ AX3
⇒ bond angles = 120°
⇒ Coordination number = 3
⇒ Trigonal planar
b) Sulfate = SO42-
The central S
-atom has four electron domains. It has no lone pairs, so the electron geometry and the molecular geometry are tetrahedral.
⇒AX4
⇒ bond angles = 190.5°
⇒Coordination number = 4
⇒Tetrahedral
c) Chlorate = ClO3-
In ClO3-, the central atom is a Chlorine.
It has 7 valence electrons. The three oxygen form a double bond giving three bond pairs. The remaining two electrons make a lone pair. The total of 4 electron pairs shows that the molecule is sp3 hybridised.
The shape of sp3 hybrid molecule is a tetrahedral. But there is a lone pair. So, the geometry is <u>pyramidal</u>.
⇒AX4
⇒ bond angles = 190.5°
⇒Coordination number = 3
⇒pyramidal
Diffference between tetrahedral and pyramidal is that tetrahedral no has a lone pair, and has 4 atoms bonded to the central atom, while pyramidal has 1 lone pair and 3 atoms bonded to the central atom.
Sulfate has a tetrahedral geometry, which is a pyramidal structure
