Burning a magnesium ribbon in the air is an addition reaction while heating potassium manganate 7 is a decomposition reaction.
<h3>Addition and decomposition reactions</h3>
Magnesium burns in air to produce magnesium oxide as follows:
Potassium manganate 7 burns to produce multiple products as follows:
Thus, the MgO will be heavier than Mg. On the other hand, 
will be less heavy than 
.
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Answer:
A piece of gold foil was hit with alpha particles, which have a positive charge. Most alpha particles went right through. This showed that the gold atoms were mostly empty space. Some particles had their paths bent at large angles. A few even bounced backward. The only way this would happen was if the atom had a small, heavy region of positive charge inside it.
Answer:
2/3
Explanation:
Crystals structures can also be seen when two elements combines together and the perfect example is Al₂O₃ which is given in the question above. Just like it is given in the question above, the kind of arrangement in the crystal structure for Al₂O₃ is called HCP which stands for Hexagonally Closed Pack.
The aluminum ions which is in form of Al³⁺ occupies the two-third[2/3] positions while the position that the oxygen ion occupies is one[1].
As the concrete has cement, gravel, crushed rocks, sand, and water of different physical state and can be separated by physical methods hence it should be called as a mixture.
As the components have significant physical boundaries which clearly identify their presence, the mixture is heterogeneous and not homogeneous.
Thus this is a concrete is a heterogeneous mixture of cement, gravel, crushed rocks, sand, and water
