Matter And Energy Unit Test 1.5

The Periodic Table is used by scientists to determine the properties of elements. It is a tabular arrangement of chemical elements, organized based on their atomic number, electron configuration, and recurring chemical properties. The table provides information about each element's atomic mass, symbol, atomic number, and other important characteristics. By referring to the Periodic Table, scientists can understand the properties of elements such as their reactivity, valence electrons, and physical states, which are crucial for conducting experiments and understanding the behavior of different substances.

Diagram 2 best represents molecules of matter in the solid phase because the molecules are tightly packed together in a regular, organized pattern. This arrangement is characteristic of solids, where the molecules have strong attractive forces holding them in place and vibrating in fixed positions. Diagrams 1, 3, and 4 show molecules that are either too spread out or not in a regular pattern, which are not characteristic of solids.

Atoms are the tiny particles that make up all matter. They are the basic building blocks of everything in the universe, including genes, minerals, and cells. Genes are segments of DNA that contain instructions for building proteins, not particles of matter. Minerals are naturally occurring inorganic substances, but they are composed of atoms. Cells are the basic units of life, but they are made up of atoms as well. Therefore, atoms are the correct answer as they are the fundamental particles that make up all matter.

Water is usually found in nature as a liquid, solid, and gas. In its liquid form, it is commonly seen in lakes, rivers, and oceans. It can also exist as a solid in the form of ice, which is found in glaciers and polar regions. Additionally, water can be present as a gas in the form of water vapor, which is found in the atmosphere. This versatility in its states of matter is due to the unique properties of water molecules, such as hydrogen bonding.

When hydrochloric acid is added to zinc, a chemical reaction occurs. The hydrochloric acid reacts with the zinc to form zinc chloride, a new substance, and hydrogen gas is released. This is a clear indication of a chemical reaction taking place, as new substances are formed and there is a release of gas. A physical change, on the other hand, does not result in the formation of new substances. Photosynthesis and evaporation are unrelated processes and do not apply to this situation.

When water changes from a liquid to a gas, it undergoes the process of evaporation. This requires the input of energy in the form of heat. Heat energy is absorbed by the water molecules, causing them to gain enough energy to break the intermolecular forces holding them together and transform into a gaseous state.

The correct answer is shape because when the student crumples up the sheet of paper, its physical appearance changes from being flat to having a different form or structure. The paper no longer retains its original shape and has been altered in terms of its arrangement or configuration.

When a person speaks into a telephone, the sound energy is converted mostly into electrical energy. This is because the sound waves produced by the person's voice cause the microphone in the telephone to vibrate. These vibrations are then converted into electrical signals that can be transmitted through the telephone lines.

On a sunny day, the shirt dries because the water molecules in the shirt gain heat energy from the sun. This increase in heat energy causes the water molecules to evaporate, meaning they transform from a liquid state to a gaseous state. As the water molecules evaporate, they leave the shirt, resulting in the shirt drying.

The elements on the Periodic Table are arranged in order of increasing atomic number. This is because the atomic number represents the number of protons in an atom's nucleus, which determines its identity as a specific element. By arranging the elements in order of increasing atomic number, the Periodic Table allows for a systematic organization of elements based on their properties and characteristics.

The chemical symbol CO represents the compound carbon monoxide. A compound is a substance composed of two or more elements chemically combined in a fixed ratio. In this case, carbon (C) and oxygen (O) are combined to form carbon monoxide (CO). Therefore, CO is the only substance among the options provided that is a compound.

An electron is negatively charged because it has a surplus of negative particles called electrons. On the other hand, a proton is positively charged because it has a surplus of positive particles called protons. Therefore, the statement that an electron is negative and a proton is positive is true.

The substances helium and oxygen are elements because they cannot be broken down into simpler substances by chemical means. Hydrochloric acid and carbonic acid are not elements, as they are compounds made up of multiple elements. Carbon dioxide and water are also compounds, consisting of carbon and oxygen, and hydrogen and oxygen respectively.

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In diagram 2, the symbols representing the atoms are rearranged, indicating that a chemical change has occurred. In the other diagrams, the symbols remain the same, suggesting that no chemical change has taken place.

The diagram shows a light wave passing through a material and changing direction. This phenomenon is known as refraction. Refraction occurs when light waves travel from one medium to another with a different optical density, causing the waves to bend. Therefore, the correct answer is "Light waves are refracted by some materials."

The symbols in the model represent atoms. In the diagram, "H" represents a hydrogen atom and "O" represents an oxygen atom. These atoms are arranged in a specific geometric structure to form a molecule of water (H2O).

The water level in the glass of water decreases is evidence that the water is undergoing a phase change because when water evaporates and changes from a liquid to a gas, the level of water in a container will decrease.

When light passes from one medium (such as air) to another medium (such as water) with a different refractive index, it changes direction. This phenomenon is called refraction. In this case, when the light from the fish travels from the water to the air, it bends away from the normal (the line perpendicular to the surface of the water). As a result, the apparent position of the fish appears higher than its actual position, causing the boy to see the fish at position A instead of position B.

The diagram B represents electromagnetic energy with the shortest wavelength because the wavelength is inversely proportional to the energy. In the electromagnetic spectrum, shorter wavelengths correspond to higher energy. Therefore, diagram B, which has the shortest wavelength among the given options, represents electromagnetic energy with the highest energy level.

Sound waves are created by vibrations because sound is a mechanical wave that requires a medium to travel through. When an object vibrates, it creates disturbances in the surrounding medium, which propagates as sound waves. These waves consist of compressions and rarefactions that travel through air, water, or any other medium, allowing us to hear sound. Therefore, the statement "are created by vibrations" accurately describes the common characteristic of sound waves.

When air is pumped out of the vacuum jar, the sound level of the ringing bell decreases because sound requires a medium, such as air, to travel through. In the absence of air, there are no particles to vibrate and carry the sound waves, resulting in the sound becoming fainter and eventually disappearing.

Convection currents are the correct answer because heat energy is transferred within liquid water in a pond through the movement of the water itself. As the water near the bottom of the pond is heated, it becomes less dense and rises to the surface, while the cooler water near the surface sinks to the bottom. This creates a continuous circulation of water, which allows heat energy to be transferred throughout the pond. This process is known as convection and is a common method of heat transfer in fluids.

Sound requires a medium to travel through, such as air, water, or solids. In a vacuum, there is no medium for sound waves to propagate, so sound cannot travel. This is because sound waves are mechanical waves that rely on the vibration of particles in a medium to transmit energy. In the absence of particles, as in a vacuum, there is no medium for the sound waves to pass through, resulting in the inability of sound to travel.