Berdasarkan sejarahnya, tarian ini lahir dan berkembang di wilayah internal Kesultanan Serdang Bedagai, Deli Sedang, Sumatera Utara. Sebelum menggunakan nama “semudah dua belas”, tarian ini pada awalnya bernama tarian Pulau Sari hasil kreasi orang Melayu asli bernama Sauti pada tahun 1940-an.
To take the percent by mass of this element, we use the
formula:
% mass = (mass of element / mass of ore) * 100%
% mass = (47.5 g / (660 kg * 1000 g / kg)) * 100*
<span>% mass = 7.20 x 10^-3 %</span>
Alpha particles are relatively heave and can be stopped by a sheet of paper.
Answer:
D. Zn → Zn²⁺ + 2e⁻, 2H⁺ + 2e⁻ → H₂.
Explanation:
- It is a redox reaction that is consisted of two half-reactions:
Oxidation reaction:
Zn losses 2 electrons and is oxidized to Zn²⁺:
<em>Zn → Zn²⁺ + 2e⁻.</em>
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Reduction reaction:
H⁺ gains 1 electron and is reduced to H:
<em>2H⁺ + 2e⁻ → H₂.</em>
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<em>So, the right choice is: D. Zn → Zn²⁺ + 2e⁻, 2H⁺ + 2e⁻ → H₂.</em>
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Answer:
A.The two ends are like poles
Explanation:
Magnets are composed of a north pole and a south pole. If two like poles of a magnetic are placed near each other, the two ends seem to push apart.
The reason for this is that, when like poles of two magnets are made to face each other, the lines of forces are in opposite directions, hence the magnets repel.
If unlike poles of two bar magnets are made to face each other, the magnetic lines of force are now in the same direction therefore the unlike poles attract each other.
