Here are answers with explanations for each question:
1. **Solid**
The tightly packed particles in rows and columns suggest a solid state of matter, where particles have fixed positions and vibrate in place.
2. **Liquid**
The description of "small pea seeds move around each other but do not bounce off" indicates a liquid state, where particles are close together but can flow and slide past one another.
3. **Pack the bowl with marbles and then tap it gently.**
This action simulates the closely packed arrangement of particles in a solid, which can only vibrate in fixed positions.
4. **Fireworks exploding**
This represents a chemical change, as new substances are created during the explosion, and energy is released.
5. **The changed substance retains its unique properties.**
In a physical change, the composition of the substance remains the same, meaning its properties do not change.
6. **The properties of carbon dioxide and oxygen are different.**
This indicates a chemical change, where the reactants (carbon dioxide and water) form new products (food and oxygen) with different properties.
7. **30 g**
The mass of water would increase by the mass of the sugar dissolved, so if 30 g of sugar is added, the mass of the solution increases by 30 g.
8. **14 g**
According to the law of conservation of mass: Total mass of reactants = Total mass of products. Thus, 10 g of hydrochloric acid + 20 g of zinc = 24 g of zinc chloride + mass of hydrogen. The mass of hydrogen gas is 10 g + 20 g - 24 g = 6 g.
9. **Mass is conserved when 200 g of water undergoes a physical change.**
Mass conservation means that the total mass remains constant. For example, when ice melts into water, the mass remains 200 g before and after the change, which can be demonstrated by weighing the container before and after the melting process.
10. **Molecules speed up**
Increasing the temperature typically increases the kinetic energy of molecules, leading to faster movement and increased reaction rates.
11. **Lower at 39 °F**
Higher temperatures generally provide more energy to the particles (molecules), increasing the chances of them bouncing off each other and reacting.
12. **Less than 68 seconds as the rate of reaction is higher for tap water**
Tap water is typically warmer than cold water, which would speed up the dissolving process of the tablet.
13. **Particles are farther apart in gases so substance X is water vapor.**
The higher bar represents a greater volume associated with water vapor (gas) compared to liquid water, indicating that gas particles are more spread out.
14. **The law of conservation of mass does not hold true in this case.**
Initially, 123.6 g of copper carbonate decomposed into a residue weighing 79.6 g. If we calculate the missing mass: 123.6 g - 79.6 g = 44 g. This loss of mass suggests that gases (likely carbon dioxide) escaped during the process, violating the conservation of mass principle.