1.
Which type of matter consists of two or more substances that are NOT chemically combined?
Correct Answer
B. Mixtures
Explanation
Mixtures consist of two or more substances that are not chemically combined. In a mixture, the substances retain their individual properties and can be physically separated. This is different from compounds, which are formed when elements chemically combine and lose their individual properties. Atoms are the basic building blocks of matter, while elements are pure substances made up of only one type of atom. Therefore, the correct answer is mixtures.
2.
Substances that CANNOT be broken down into other substances are called __________.
Correct Answer
D. Elements
Explanation
Elements are substances that cannot be broken down into other substances. They are the simplest form of matter and are made up of only one type of atom. Unlike compounds, which are made up of two or more different elements chemically combined, elements cannot be further broken down by chemical means. Liquids, mixtures, and compounds can all be broken down into simpler substances, but elements cannot.
3.
In chemistry, elements are represented by _________________.
Correct Answer
C. Symbols
Explanation
In chemistry, elements are represented by symbols. These symbols are usually one or two letters that are derived from the element's name. For example, the symbol for carbon is C, and the symbol for oxygen is O. These symbols are used to write chemical formulas and equations, and they provide a concise way to represent and communicate information about elements and compounds.
4.
The measurement of how much matter an object contains is its _________________.
Correct Answer
C. Mass
Explanation
Mass is the measurement of how much matter an object contains. It is a fundamental property of an object and is independent of its location or the force acting on it. Density refers to the mass per unit volume of a substance, weight is the force of gravity acting on an object, and volume is the amount of space occupied by an object. Therefore, mass is the correct answer as it directly relates to the amount of matter in an object.
5.
Which of the following is NOT true of a compound?
Correct Answer
C. It is made of substances that keep their individual properties.
Explanation
A compound is made up of two or more elements that are chemically combined in a specific ratio. When elements combine to form a compound, they lose their individual properties and form new substances with different properties. Therefore, the statement "It is made of substances that keep their individual properties" is not true of a compound.
6.
The SI unit for mass is the ___________________.
Correct Answer
A. Kilogram
Explanation
The SI unit for mass is the kilogram. The kilogram is the base unit of mass in the International System of Units (SI). It is defined as the mass of the International Prototype of the Kilogram (IPK), a platinum-iridium cylinder kept at the International Bureau of Weights and Measures. The kilogram is widely used in scientific and everyday contexts for measuring the mass of objects.
7.
How would you calculate the density of an object?
Correct Answer
C. Divide its mass by its volume
Explanation
To calculate the density of an object, you need to divide its mass by its volume. Density is defined as the amount of mass per unit volume, so dividing the mass by the volume gives you the density value.
8.
What is the density of a block of wood with a volume of 10 cubic centimeter and a mass of 100 grams?
Correct Answer
A. 10 grams/cubic centimeter
Explanation
The density of a substance is calculated by dividing its mass by its volume. In this case, the mass of the block of wood is given as 100 grams and the volume is given as 10 cubic centimeters. Therefore, the density can be calculated as 100 grams / 10 cubic centimeters, which simplifies to 10 grams/cubic centimeter.
9.
All elements are composed of extremely small particles called _______________.
Correct Answer
B. Atoms
Explanation
Atoms are the basic building blocks of all elements. They are extremely small particles that make up everything in the universe. Molecules, mixtures, and compounds are combinations of atoms, but atoms themselves are the fundamental units of matter.
10.
A group of atoms that are bonded together are called __________________.
Correct Answer
D. Molecule
Explanation
A group of atoms that are bonded together are called a molecule. Molecules can be made up of the same type of atoms or different types of atoms. They are the smallest units of a compound that retain the chemical properties of that compound. Molecules play a crucial role in various chemical reactions and interactions.
11.
What holds atoms together in a molecule?
Correct Answer
B. Chemical bonds
Explanation
Chemical bonds hold atoms together in a molecule. These bonds are formed when atoms share or transfer electrons to achieve a stable electron configuration. This sharing or transfer of electrons creates attractive forces between the atoms, keeping them bonded together in a molecule. Temperature, gravity, and density do not play a direct role in holding atoms together in a molecule.
12.
What technique did miners use to separate dirt from gold?
Correct Answer
D. Panning
Explanation
Miners used the technique of panning to separate dirt from gold. Panning involves swirling a mixture of dirt and water in a shallow pan, causing the gold particles to sink to the bottom while the lighter dirt is washed away. This method takes advantage of the density difference between gold and dirt, allowing miners to easily separate the valuable gold from the unwanted material.
13.
What does this diagram represent?
Correct Answer
A. Molecules
Explanation
The diagram represents molecules. This is indicated by the fact that the other options - an atom, an element, and nothing - do not accurately describe the diagram. The diagram likely shows multiple atoms bonded together, forming a molecule.
14.
What does this picture represent?
Correct Answer
C. A heterogeneous mixture
Explanation
This picture represents a heterogeneous mixture. A heterogeneous mixture is a combination of different substances that are visibly distinct and not uniformly distributed throughout the mixture. In the picture, there are clearly different components that can be identified, indicating that it is not a homogeneous mixture where the components are evenly distributed. Additionally, it is not an element because an element is a pure substance made up of only one type of atom. Lastly, it is not a pure substance because a pure substance consists of only one type of substance and cannot be separated into other substances.
15.
What does this picture represent?
Correct Answer
A. A pure substance
Explanation
This picture represents a pure substance because it shows a single element or compound that is not mixed with any other substances. A pure substance has a uniform composition and distinct properties, which can be seen in the picture.
16.
Which of the following examples below represents a homogeneous mixture?
Correct Answer
D. A glass of water
Explanation
A glass of water represents a homogeneous mixture because it is a combination of water molecules that are uniformly distributed throughout the glass. In a homogeneous mixture, the components are evenly mixed at a molecular level, resulting in a uniform composition and appearance. In the case of a glass of water, the water molecules are evenly dispersed, making it a homogeneous mixture.
17.
What shows the ratio of elements in a compound?
Correct Answer
C. A formula
Explanation
A formula shows the ratio of elements in a compound. In chemistry, a compound is made up of two or more different elements combined in a specific ratio. The formula of a compound provides information about the types of elements present and the number of atoms of each element in the compound. This allows scientists to understand the composition and structure of the compound. Therefore, a formula is the correct answer as it accurately represents the ratio of elements in a compound.
18.
Most matter occurs in the environment as _________________.
Correct Answer
C. Mixtures
Explanation
Matter in the environment is commonly found in the form of mixtures. A mixture is a combination of two or more substances that are physically combined and can be separated by physical methods. This is different from elements, which are pure substances made up of only one type of atom, and compounds, which are pure substances made up of two or more different types of atoms chemically combined. Therefore, mixtures are the most common form of matter found in the environment.
19.
The measure of the force of gravity on an object is called its _______________.
Correct Answer
C. Weight
Explanation
Weight is the measure of the force of gravity on an object. It is different from mass, which is the amount of matter in an object. Weight depends on the gravitational pull of the planet or celestial body on which the object is located, whereas mass remains constant regardless of the location. Length and height are measurements of distance and do not relate to the force of gravity on an object.
20.
True or False -- The density of a substance varies with the samples of that substance.
Correct Answer
B. False
Explanation
The density of a substance does not vary with different samples of that substance. Density is an intrinsic property of a substance and is defined as the mass per unit volume. It remains constant regardless of the size or amount of the substance being measured. Therefore, the statement that the density of a substance varies with the samples of that substance is false.
21.
The measurement of the amount of space an object takes up is its ______________.
Correct Answer
D. Mass
Explanation
The measurement of the amount of space an object takes up is not its volume, density, or formula. The correct answer is mass. Mass refers to the amount of matter in an object and is typically measured in units such as kilograms or pounds. It is different from volume, which measures the amount of space an object occupies.
22.
A change in matter that produces new substances is called a _________________.
Correct Answer
C. Chemical change
Explanation
A change in matter that produces new substances is called a chemical change. This type of change involves the rearrangement of atoms or molecules, resulting in the formation of different substances with new chemical properties. Unlike physical changes, which only alter the physical state or appearance of a substance without creating new substances, chemical changes involve the breaking and forming of chemical bonds. Examples of chemical changes include combustion, rusting, and fermentation.