No. When water first begins to cool down, it contracts. However, as it gets colder and eventually freezes, it begins to expand.
You can test this by freezing water in a water bottle: when you take it out of the freezer, the cap might have popped off or cracks may have formed in the sides of the bottle.
Answer: Water expands when frozen, not contracts.
Answer:
26.7% is the percent composition by mass of sulfur in a compound named magnesium sulfate.
Explanation:
Molar mass of compound = 120 g/mol
Number of sulfur atom = 1
Atomic mass of sulfur = 32 g/mol
Percentage of element in compound :

Sulfur :

26.7% is the percent composition by mass of sulfur in a compound named magnesium sulfate.
Answer:
element having 2+ valence electrons can transfer its more than one electron that is 2 electron completely.
Explanation:
- Group IIA have 2+ valency and two electrons in its valance shell.
- Its Electropositivity is high and have the tendency to donate it two electrons.
- Element of IIA form ionic with most electronegative element.
Examples:
Cu²⁺, Mg²⁺, Sr²⁺ are examples having 2+ valance electron
one of the following is examples of element that have 2+ valence electrons
MgCl₂
Atomic number of Magnesium (Mg) is 12
Electronic Configuration of Mg:
1s², 2s², 2p⁶, 3s²
or
K =2
L = 8
M = 2
So, it have to give its 2 electrons to form a stable compound.
Similarly
Chlorine atomic number is 17
Electronic Configuration of Chlorine:
1s², 2s², 2p⁶, 3s², 3p⁵
or
K =2
L = 8
M = 7
So, it have to gain one electrons to form a stable compound and complete its octet.
So,
Two chlorine atom as a molecule gain 2 electrons from Mg²⁺ atom
So one Mg²⁺ and 2 Cl⁻ atoms form an ionic bond
where in this ionic bond Mg²⁺ transfer its 2 valence electron completely and chlorine molecule accept 2 electrons.
Cl-----Mg------Cl
So the Answer is
element having 2+ valence electrons can transfer its more than one electron that is 2 electron completely.
Answer:
325mg of Aspririn
Explanation:
First you should note the information that the problem gives you:
- The bottle of Aspirin has 5gr (grains)
- 1gr(grain) = 65mg (miligrams)
Also, the problem is asking about how many aspirin are in 5 gr (grains), so you should use a conversion factor, as follows:
-First you should put the quantity you need to convert:

-Then you write the denominator of the conversion factor that must have the same units that you want to convert, in this case gr:

-Then you write the numerator with the units that you want to obtain and the numerical equivalence between the units, in this case:

-Finally you multiply numerators and divide by denominators:
