Your answer for this would be A. Mixtures cannot be separated by physical meansA pure substance is heterogeneous.
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The molarity of a 27%(v/v) aqueous ethanol solution is 4.63 M
calculation
convert 27%(v/v) to fraction = 27ml/100 ml
use density to convert 27ml to grams = 27 ml x0.79 g/ml = 21.33 g
find the number of moles of C2H6O
moles = mass/molar mass of C2H6O(46.07 g/mol)
moles is therefore = 21.33 g /46.07 g/mol =0.463 moles
find the molarity = moles /volume in liters
volume in liter = 100 ml/1000 = 0.1 L
molarity is therefore = 0.463 mole/0.1 L = 4.63 M
Answer:
Change in velocity (\Delta v) is acceleration (a) times time (t)
Acceleration a=1.2\ m/s^{2}
Time t=10\ s
So \Delta v=at=1.2\ m/s^{2}*10\ s=12\ m/s
The initial velocity is then 16\ m/s-12\ m/s=4\ m/s
Easy Answer: 4m/s
Explanation:
Answer:
Explanation:
Valance electrons are loosely held electrons of an atom. They are involve in chemical reaction. Consider the example of metals such as group two metals. All these have two valance electrons. They needed six electrons to complete the octet or loses two valance electrons to get complete octet. Thus its easier to remove two electrons than getting six electrons. These metals remove two electrons and form cations.
Now consider the example of nonmetals such group sixteen. They needed two electrons to get complete octet or remove six electrons to get complete octet. Thus its easier for them to get two electrons and they form anion. When group two metals cation and group sixteen anions combine they form compound and chemical reaction occur.
Group two metals also combine with halogens. Two halogens atoms combine with one alkaline earth metal atom to cancel the charge and make compound neutral.
They react with oxygen and form oxide.
2Ba + O₂ → 2BaO
2Mg + O₂ → 2MgO
2Ca + O₂ → 2CaO
Oxygen carry -2 charge while Ca, Mg and Ba +2 and make the compound neutral because charges are equal in magnitude.
With sulfur,
Mg + S → MgS
Ca + S → CaS
Ba + S → BaS
Sulfer carry -2 charge while Ca, Mg and Ba +2 and make the compound neutral because charges are equal in magnitude.
In a gas molecules have to scatter off molecules to exchange energy in larger distances, so the probability of transfer is much smaller. Air is a bad conductor because, to conduct heat current molecules should absorb heat and transmit it to neighbor by vibrating.
