Predict whether litmus paper will turn red or blue when dipped in:
a. washing powder ( containing sodium carbonate )
b. orange juice ( containing citric acid )
c. lemonade ( containing H2CO₃ )
d. cleaner ( containg NH₃ )

a. blue, b. red, c. red, d. basic - blue

Explanation:

a.washing powder ( containing sodium carbonate ) basic -blue

b. orange juice ( containing citric acid )- acidic -red

c. lemonade ( containing H2CO₃ )-acidic - red

d. cleaner ( containg NH₃ )- basic - blue

number of molecules / avogadro's number * molecule molecular = mass

explanation:

we define a gram-molecular weight as the mass of one mole of any element or compound. a mole contains avogadro's number of units (molecules) –  

6.022

x

10

23

. so, dividing the number of molecules by avogadro's number gives us the number of moles. multiplying that by the molecular weight gives us the mass. from the periodic table we find the gram-molecular weight of u to be238 and of f to be19. so,  

u

f

6

will have a gram-molecular weight of 352g.

alkaline metals are lithium, sodium, rubidium, potassium, cesium and francium.

alkali metals have electronegativity from 0.7 to 1, lowest in periodic table of elements, which means that alkali metals (i group in periodic table) has positive oxidation number in compounds.

electronegativity is a chemical property that describes the tendency of an atom to attract a shared pair of electrons towards itself.

alkaline metals (far left in main group) have lowest ionizations energy and easy remove valence electrons,

for example, potassium is the alkali metal and has a single valence electron in the outer electron shell.

electron configuration of potassium is: ₁₉k 1s²2s²2p⁶3s²3p⁶4s¹.

they can not exist alone in nature, because they are very reactive.