Grade 7 Chapter 7 Bump Up Quiz

The given description indicates that the particles in the substance are vibrating in place, which suggests that the particles are closely packed together and have a strong attraction to each other. This characteristic is typical of a solid, where the particles are arranged in a regular pattern and have a fixed shape and volume.

The correct answer is "the same" because in a pure substance, all particles are identical in terms of their composition and properties. They have the same chemical formula and are made up of the same type of atoms or molecules. This uniformity allows the substance to have consistent physical and chemical characteristics throughout.

The rock-like material appears to be one color from a distance, but upon closer examination, it is revealed to have many different colors. This indicates that the material is a mechanical mixture, as it is made up of different components that can be visually distinguished. A pure substance would have a uniform composition throughout, while a solution would be a homogeneous mixture with the different colors evenly distributed. Therefore, the best classification for this material is a mechanical mixture.

When you boil salt water, the water molecules gain enough energy to break their bonds and escape into the air as vapor, which is the process of evaporation. However, the salt particles are too large and cannot evaporate with the water. Therefore, as the water evaporates, the salt remains behind in the container.

When a chocolate bar is melted, the heat causes the chocolate particles to gain energy and become excited. This increased energy causes the particles to move more rapidly and spread further apart from each other. As a result, the chocolate melts and becomes a liquid. The option "They get excited and move further apart" accurately describes this process of melting chocolate.

The particle theory states that all substances have tiny particles, all particles have spaces between them, and all particles are attracted to one another. However, it does not state that all particles in any substance are the same. This means that particles in different substances can have different properties, such as size, shape, and composition.

In solids, the particles are closely packed together and have limited freedom of movement. However, they still possess kinetic energy in the form of vibrations. These vibrations occur due to the thermal energy present in the solid, causing the particles to oscillate around their equilibrium positions. Therefore, the correct answer is "vibrate".

When you boil water, the heat causes the water molecules to gain energy and move faster. As a result, some of the water molecules at the surface gain enough energy to break free from the liquid phase and become water vapor or steam. This process is known as evaporation. Therefore, the steam rising from the surface of the water when boiling is an example of evaporation.

The given explanation describes particles that can slip past each other and cannot hold their shape. This behavior is characteristic of a liquid state of matter. In a solid state, particles are tightly packed and cannot move freely. In a gas state, particles are far apart and move randomly. In a plasma state, particles are highly ionized and have a high energy level. Therefore, the correct answer based on the given explanation is liquid.

Milk is a mixture composed of various components such as water, proteins, fats, lactose, and minerals. These components are uniformly distributed throughout the milk, resulting in a homogeneous mixture. Therefore, milk can be classified as a solution.

When you take a hot shower, the steam from the hot water comes into contact with the cold surface of the mirror. This causes the steam to lose heat energy and slow down, eventually turning into liquid water droplets. This process is called condensation, which refers to the change of state from a gas (steam) to a liquid (water) when it loses heat.

The correct answer is "Used my notes". This implies that the person studied by referring to their own notes, which suggests that they had taken notes during their classes or previous study sessions. Using notes can be an effective study method as it helps in reviewing and reinforcing the material learned.

A homogeneous mixture refers to a combination of substances that are uniformly distributed throughout, resulting in a consistent composition and appearance. In the case of a container of salt or a glass of distilled water, both substances are completely dissolved and evenly distributed, creating a homogeneous mixture. This means that every part of the mixture will have the same proportion of salt or water, making it difficult to distinguish between the two components.

The correct answer is 40-60min. This suggests that the person studied for a considerable amount of time, between 40 to 60 minutes, in preparation for the quiz. They dedicated a substantial period to review the material and enhance their understanding, indicating a higher likelihood of performing well on the quiz compared to those who studied for shorter durations or did not study at all.