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Tell if each photo represents an item composed of an element, compound, or mixture. An element contains just one type of atom. A compound contains two or more different atoms joined together. A mixture contains two or more different substances that are only physically joined together, not chemically.
molecule. Elements can be in the form of molecules. For example, oxygen consists of molecules which are two oxygen atoms bound together (O2). Compounds can also be in the form of molecules. An example of a molecule which is a compound is carbon dioxide (CO2). Water is also a compound which consists of molecules.
Do elements consist of atoms or molecules ? • Some elements exist in the form of atoms e.g. the noble bases neon (Ne), argon (Ar), krypton (Kr), xeon (Xe) and radon (Rn). • Other elements exist in the form of molecules. For example many common gases exist as diatomic molecules e.g. oxygen (O 2), hydrogen (H 2), and nitrogen (N 2).
A molecule is a combination of at least two atoms in a specific arrangement held together by chemical forces (chemical bonds). A molecule may be an element or a compound. Some elements that naturally exist as molecules include: Br 2, I 2, N 2, Cl 2, H 2, O 2, F 2, and C 60 and S 8 BrINClHOF (The super 7)
An element is a pure substance which contains identical atoms or molecules with only one type of atomic core. 2. A compound is a pure substance which contains identical molecules with two or more types of atomic core. 3. A mixture is a material which has two or more types of molecules.
Shown are examples that illustrate the diverse roles that small molecules play in living systems. Glucose is a sugar that is used as an energy source; cholesterol is a component of animal cell membranes; pyridoxine is a vitamin (B 6); and serotonin is a neurotransmitter.
Elements are the fundamental materials of chemistry and are characterized by the fact that they cannot be broken down into simpler substances by chemical means. Only 88 occur naturally and only the first 92 are typically used in chemical laboratories.
