Since 1800, almost 200 sincere but erroneous reports ofthe discovery of new chemical elements have been made.Why have mistaken reports of new elements been sonumerous? Why is it relatively easy to prove that a material is not a chemical element, but difficult to prove absolutely that a material is an element?

Q: 10. Nitrogen, hydrogen, and ammonia (NH3) are all composed of molecules. What is it about a molecule…

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Q: Most substances are composed of _________ rather than elemental substances

A: Element:  A substance that cannot be broken down into simpler substances by chemical or physical…

Q: Which of the following are elements, which aremolecules but not compounds, which are compoundsbut…

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Q: Should the elemental symbol for lead be written as Pb or PB? What confusion could arise if the wrong…

A: Elemental symbol for lead is Pb and it should be Pb .

Q: IN YOUR OWN WORDS, DIFFERENTIATE COMPOUND, ATOMS, ELEMENTS AND MOLECULES. GIVE EXAMPLES FOR EACH.…

A: A particular atom will have the same number of protons and electrons and most atoms have at least as…

Q: Fill in the blanks by writing the name of the definition: is a substance made up of only a single…

A: an element is a substance that cannot be broken down into any other substance every element is made…

Q: Which if the following ionic compounds would contain the most total number of elements? (For…

A: Explanation to the correct answer is given below

Q: Search the web or your textbooks for an illustration of Mendeleev’s periodic table. How many…

A: Given : Mendeleev periodic table  To find : Describe it properly Solution : There are thousands of…

Q: Take the mass measurement with nitrogen (28 dalton or atomic mass units per molecule) and the mass…

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Q: is carbon dioxide classified as an element?

A: Given name is Carbon dioxide  We need to explain can cabon dioxide be classified as an element or…

Q: Which of the following elements are metals? C Ca Br Co Ni Ar Li Al O ?

A: Metal are electropositive in nature  Metals are have less electronegativity  In periods from left to…

Q: The elemental symbols for an element are O 1or 2 letter symbols with the 1s* letter upper case and…

A: Each element has unique symbols.

Q: Molecules and compounds are made up of many atoms, however, not all molecules are compounds. Which…

A: molecule: substance which have two or more atoms called molecules. compound:- substance which have…

Q: What are the chemical symbols for antimony, arsenic, aluminum, boron, gallium, germanium, indium,…

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Q: The single proton that forms the nucleus of the hydrogen atom hasa radius of approximately 1.0 *…

A: Solution- when 1 m = 100 cm   and 1 m = 1012 pm   now, proton radius =1.0×10-13cm…

Q: A compound consists of elements combined in a fixed ratio. True or False

A: An element is a pure chemical substance made of same type of atoms.  The compounds are made up of…

Q: In our modern view of matter and energy, is the law of massconservation still relevant to chemical…

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Q: 2.77 Identify the following as elements or compounds: NH3, N2, Sg, NO, CO, CO,, H2, SO2.

A: Matter is any substance that occupies space and volume. Matter is classified into pure substances…

Q: The mass of a single vanadium atom is 8.46×10-23 grams. How many vanadium atoms would there be in a…

A: Density is the physical quantity that relates mass of a substance with its volume.Mathematically,…

Q: Which of the following gases are elements? O NH, O 0, O N,0 Rn Ar O 0, so, O H,S HCN NO NO, O He

A: Elements are the pure substances that are made up of only one kind of atoms, We are given some list…

Q: Vhich statement about pure substances and molecules is correct? Molecules cannot be pure substances.…

A: molecules are made up of two or more atoms combining in a specific ratio. Pure substances are those…

Q: What is the edge length (in cm) of a titanium cube that con- tains 2.55 x 1024 titanium atoms? The…

A: Calculate the number of moles as follows, Number of moles =2.41×10246.022×1023=0.4×10=4 moles Now,…

Q: Which of the following are pure substances? Explain. (a) Calcium chloride, used to melt ice on…

A: Since you've posted multiple sub-parts, we'll solve only the first three sub-parts for you. To get…

Q: This picture represents Atoms of an element O Molecules of an element O Molecules of a compound A…

A: An atom is a single entity whereas a molecule consists of two or more atoms. Atoms in a molecule…

Q: Why was it necessary for separation techniques and methodsof chemical analysis to be developed…

A: Law of definite composition states that the composition of a particular compound is the same no…

Q: Matter consists of tiny particles that can combine in specific ratios to form substances with…

A: A theory gives us a well-structured explanation of an observed phenomenon that is confirmed through…

Q: Which of these statements is a consequence (follows from) the Law of Definite Proportions? O All…

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Q: A pure substance is: O composed of two or more regions with different compositions. O composed of…

A: Here we have to define pure substance.

Q: Based on the following word descriptions, write the formula for each of the indicated substances.a.…

A: A formula of any compound which represents number of the all types of atoms of that compounds…

Q: Define the Laws of Definite and Multiple Proportion?

A: Law of multiple proportions states “If two elements can combine to form more than one compound, the…

Q: 4. A bottle of Gatorade has a volume of 516 mL. What is this volume in quarts(qt)? (1 qt = 0.946 L )…

A: 4), Given. 0.946 L=1 qt We can say that, 946 mL=1 qt 1 mL=1946qt So, 516 mL=1946×516qt…

Q: 1. Which of the following is NOT a pure element Nitrogen Carbon Dioxide

A: Pure substances :- Pure substances consist of single type of particles. Pure substances can be…

Q: Musical instruments like trumpets and trombones are madefrom an alloy called brass. Brass is…

A: Homogeneous mixtures are those mixtures in which composition is uniform throughout the mixture.…

Q: What are the chemical symbols of the following elements: lithium, sodium, silicon, nitrogen,…

A: To find: The chemical symbols of given elements

Q: Tennessine has two naturally occurring isotopes.  Tennessine-293 has an atomic mass of 292.9498 and…

A: Given  Atomic mass of Tennessine -293 ( m1 )  = 292.9498 amu Atomic mass of Tennessine - 296 ( m2 )…

Q: How do the molecules of a compound differ from the moleculesof an element?

A: Molecules are group of atoms where the atoms are held together by a chemical bond. They can result…

Q: Which methods separate a mixture according to the size of the particles? distillation and…

A: Given: To identify the methods which separate the mixture based on the size of the particles.

Q: True or false is an atom is the smallest building block of matter

A: False

Q: Fill in the blanks by writing the name of the definition: _________ is a substance made up of only…

A: Matter classified into element compound mixture

Q: Which among the following is a compound? salt crystals O charcoal O sulfur powder O iron filings

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Q: Defend or refute the statement • The separation of a mixture may result in the production of an…

A: Mixture is a composition where two or more different components are mixed . The process of parting…

Q: IV. Tell whether if the following is an example of homogeneous mixture or heterogeneous mixture.…

A: Homogeneous and heterogeneous mixture If you can see more than one phase of matter or different…

Q: 1. Water and sodium chloride are both considered substances as well as compounds, but water exists…

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Q: What is the law of definite composition? And what are some examples of matters that obey this law?

A: The law of definite composition states that any chemical compound will always contain a fixed ratio…

Q: Classify the statements pertaining to elements and compounds as either true or false. True False…

A: We are given different statements in the image we have to classify the statement as true and false:…

Q: Musical instruments like trumpets and trombones are madefrom an alloy called brass. Brass is…

A: Alloys are the mixture of different metals or non-metals in a fixed ratio. Brass is an alloy that is…

Q: Which element is represented by the following symbol A. Chromium B. germanium C. barium D. iron

A: The given symbol of element is                       5624X  Here,  Mass number of element = 56…

Atoms and Molecules

An atom is the smallest unit of an element that possesses all the properties of that particular element. Molecules are the smallest unit of a substance that possess all the properties of that particular substance.