X it by the molar mass of tungsten
Answer:
E) 0.90
Explanation:
In TLC (Thin-Layer-Chromatography) retention factor RF is defined as the ratio between distance of the sample and the solvent front. RF is very important in chemistry to know the composition of any sample by comparison.
In the problem, as the sample has a distance of 0,20cm from the solvent front, the distance of the sample is:
2,0cm - 0,20 cm =<em> 1,8 cm</em>. Thus, RF is:
RF = 1,8cm / 2,0cm = 0,90
<em>E) 0,90</em>
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I hope it helps!
Answer:
1. Mass of potassium (K) = 203.32 g
2. Number of mole of As = 7.53 moles
Explanation:
1. Determination of the mass of potassium (K)
Molar mass of K = 39.1 g/mol
Number of mole of K = 5.2 moles
Mass of K =.?
Mole = mass / Molar mass
5.2 = mass of K / 39.1
Cross multiply
Mass of K = 5.2 × 39.1
Mass of potassium (K) = 203.32 g
2. Determination of the number of mole of Arsenic (As)
Molar mass of As = 74.92 g/mol
Mass of As = 563.9 g
Number of mole of As =.?
Mole = mass /Molar mass
Number of mole of As = 563.9 / 74.92
Number of mole of As = 7.53 moles
Explanation:
Elements of group 1A are known as alkali metals. Elements of this group are lithium, sodium, potassium, rubidium, cesium, and francium.
All these elements are metals and every element of this group has 1 valence electron. So, in order to attain stability they will readily lose their valence electron.
Hence, elements of group 1A are very reactive.
On the other hand, elements of group 7A are also known as halogen group. Elements of this group are fluorine, chlorine, bromine, iodine, and astatine.
All these elements are non-metals and every element of this group has 7 valence electrons. So, in order to completely fill their octet these elements gain 1 electron from a donor atom.
Therefore, these elements are alo reactive in nature.
But the major difference between elements of group 1A and group 7A is that elements of group 1A are metals but elements of group 7A are non-metals.
