Answer:
a. mixtures are created through physical changes and compounds are created through chemical reactions
Explanation:
Water, or H2O, is a compound composed of the elements hydrogen (H) and oxygen (O).
Answer:
1.5 x 10²²atoms
Explanation:
Given parameters:
Mass of Br = 1.98g
Unknown:
Number of atoms
Solution:
A mole of a substance is the amount of substance contained in the avogadro's number of particles.
To solve this problem, we must first find the number of moles present in the given mass of the Br atom:
Number of moles = 
= 
= 0.025mole.
Now we know that:
1 mole = 6.02 x 10²³
0.025 mole = 0.025 x 6.02 x 10²³ = 1.5 x 10²²atoms
The Moon<span> moves </span>around<span> the </span>Earth in<span> an </span>approximately<span> circular </span>orbit<span>, going once </span>around<span> </span>in approximately<span> 27.3 </span><span>days. </span>The moon orbits quite fast: it moves about 0.5 degrees<span> per hour in the sky. So, its average movement in a day is around 13 degrees. 5 days x 13 degrees is approximately 65 degrees. </span>
Answer:
ExplanatioFirst let us compute for the molar mass of Mg(OH)2.
molar mass = 24.3 + 2 (16) + 2(1.0)
molar mass = 58.3 g/mol
So the mass is then:
mass = 3.2 mol * (58.3 g/mol)
mass = 186.56 gramsn:
