Answer:
Protons and neutrons are made up of smaller subatomic particles. When protons or neutrons get close enough to each other, they exchange particles (mesons), binding them together. Once they are bound, it takes considerable energy to break them apart.
Cold Packs
<u>Explanation:</u>
Endothermic reactions are reactions in which heat is absorbed from the surroundings and the container in which the reaction takes place is said to be very cold. In cold packs, ammonium nitrate is used, is dissolved in solution is said to be an example of endothermic reaction, in this the heat energy is absorbed from the surroundings. In this the solute increases the solubility with the rise in temperature, and also used in cold packs.
Answer:
A. Coal
Explanation:
= water displaced by rock
Water displaced by rock = volume of water after rock is dropped into the cylinder - volume of water before the rock was dropped into the water
Water displaced by the rock = 180 ml - 150 ml = 30 ml

Density of rock:
40 grams => 30 ml
x grams => 1 ml
Cross multiply
1*40 = 30*x
40 = 30x
40/30 = 30x/30
1.3 = x
Density of rock = 1.3 g per 1 ml
Recall: 1 ml = 1 cm³
Therefore,
Density of the rock = 1.3 g/cm³
1.3 g/cm³ falls within the range of 1.1 - 1.4 g/cm³
Therefore, the rock is identified as Coal.
Answer:
Ionic compounds: They have high melting points and boiling points. That is, ionic compounds are non-volatile.
Covalent compounds: They have usually low melting points and boiling points. That is, covalent compounds are usually volatile.
Answer: 5.185
Explanation: The sum for 1.55 + 0.235 + 3.4 = 5.185