Answer : Phenolphalien turn pink in the presence of a base.
Phenolphthalien : It is an indicator which is used in the acid-base titration.
In acidic medium, the phenolphthalien is colorless and the pH will be less than 7.
In basic medium, the phenolphthalien is pink in color and the pH will be greater than 7.
Phenolphthalien is slightly soluble in the water and highly soluble in alcohols.
Hence, the phenolphalien turn pink in the presence of a base.
1/4 Ao = Ao * ( 1/2)^(t/106)
t = 212
subtract 4.6 billion years
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Explanation:
potassium is metal
potassium 1
good conductors of thermal heat
The energy required to heat 40g of water from -7 c to 108 c is
1541000 joules
calculation
Q(heat)= M( mass) x c(specific heat capacity) xdelta t( change in temperature)
M= 40g= 40/1000= 0.04 Kg
C= 335,000 j/kg/c
delta T ( 108 --7= 115 c)
Q is therefore = 0.04 g x 335000 j/kg/c x 115 c = 1541,000 joules
The answer is that they all have metallic structures