Answer:

Explanation:
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In this case, since we are given 4 kg of a calcium-containing sample, in order to compute the atoms there first need to compute the mass in grams:

Next, via the molar mass and the Avogadro's number, we can compute the atoms as follows:

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It’s the third diagram. Gases are by far the least dense of the three main states of matter. Liquids and solids are of comparable density. Liquids assume the shape of their containers, and solids have a definite shape.
You can describe the particles of each state on the nanoscale to contribute more. Particles of a solid mostly vibrate in place and are rigidly locked together. Particles of a liquid flow past each other more, but are still tightly packed. Particles of a gas seldom even collide and have minimal attractions to each other.
You can expand on this by discussing the kinetic energy of each particle. Gases are the most energetic. Liquids second most. Solids least.
Answer:
A. SrSO4
Explanation:
it is insoluble in water therefore it is the precipitate formed in the reaction
Heat is energy, that can be transferred to another item, which is “less hot”.