The correct option is B.
Mendeleev was the one who originated the idea of arranging elements in the periodic table according to their chemical and physical properties. He left spaces in the periodic table and predicted the discovery of those elements that had not been discovered then. One of these elements is Gallium. He predicted that gallium is going to be a metal and he gave the properties that the element will possess. He also predicted that the element gallium will be placed under aluminium in the periodic table.
Answer:
Explanation:
Temperature and thermal energy are in a direct proportion which means that if temperature of a substance increases, its thermal energy also increases and vice versa.
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Hope this helped!
<h3>~AH1807</h3>
Answer:
23.8g
Explanation :
Convert 2.0M into mol using mol= concentration x volume
2.0M x 0.1L (convert 100mL to L since the units for M is mol/L)
= 0.2 mol
We can now find grams by using the molar mass of KBr
=119.023 g/mol (Found online) webqc.org
but can be be calculated by using the molecular weight of K and Br found on the periodic table
We can now calculate the grams by using grams=mol x molar mass
119.023g/mol x 0.2mol
= 23.8046 g
=23.8g (rounded to 1decimal place)
There are two naturally occurring isotopes of gallium: mass of Ga-69 isotope is 68.9256 amu and its percentage abundance is 60.11%, let the mass of other isotope that is Ga-71 be X, the percentage abundance can be calculated as:
%Ga-71=100-60.11=39.89%
Atomic mass of an element is calculated by taking sum of atomic masses of its isotopes multiplied by their percentage abundance.
Thus, in this case:
Atomic mass= m(Ga-69)×%(Ga-69)+X×%(Ga-71)
From the periodic table, atomic mass of Ga is 69.723 amu.
Putting the values,
Thus,
Rearranging,
Therefore, mass of Ga-71 isotope is 70.9246 amu.
Answer:
Pure water is a non conductor of electricity and dilute acids in their aqueous solutions form free ions, which conducts electricity. Thus when we need to electrolyse water, a dilute acid is added to increase its conductivity.
