Answer:
last one
Explanation:
endothermic reactions release energy
Answer:
Reactants
Explanation:
b) Compound
c) Heterogeneous mixture
d) Homogeneous mixture
An alloy, a metallic substance composed of two or more elements, as either a compound or a solution is a homogeneous mixture. The correct option is d.
An alloy is a mixture of chemical elements of which at least one is a metal. Unlike chemical compounds with metallic bases, an alloy will retain all the properties of metal in the resulting material, such as electrical conductivity, ductility, opacity, and lustre, but may have properties that differ from those of pure metals, such as increased strength or hardness.
In some cases, an alloy may reduce the overall cost of the material while preserving important properties. In other cases, the mixture imparts synergistic properties to the constituent metal elements such as corrosion resistance or mechanical strength. Alloys are defined by a metallic bonding character. The alloy constituents are usually measured by mass percentage for practical applications, and in atomic fraction for basic science studies.
Alloys are usually classified as substitutional or interstitial alloys, depending on the atomic arrangement that forms the alloy.
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Answer:
An alloy is a homogeneous mixture
Explanation:
D
Answer:
C) SO3
Explanation:
Lewis formula shows the bonding between atoms of a molecule and expresses the lone pair present in the atoms.
SO3 or Sulfur trioxide cannot be adequately described by a single Lewis formula because it has majorly 3 resonance structures because Sulfur does not follow the octet rule and can expand electrons in its outer shell.
Hence, the correct answer is C) SO3
SO3, or Sulfur Trioxide, is the molecule whose electronic structure requires the depiction of multiple resonance structures for adequate description. The rest of the species can be represented with a single Lewis structure.
The electronic structure that can only be described by drawing two or more resonance structures is SO3 (Sulfur Trioxide). This molecule has 24 valence electrons having a central atom with expanded octet. The Lewis structure is drawn in a way that three resonance structures are needed to represent the bonding in this molecule adequately. On the other hand, the rest of the species given in the options can be described using a single Lewis formula.
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Answer:
is formed of cation, and anion,
Explanation:
Naming of the ionic compounds:-
Hence, given ionic compound:-
is formed of cation, and anion,
Thus, the name must be Cobalt(II) nitrate.
Answer:
d. a polymer of amino acids
Explanation:
Got it right on the test.
Answer:
D
Explanation:
The building blocks or monomers of proteins are called amino acids. There are 20 different kinds of amino acids. The amino acids form long chains that are proteins. Therefore, proteins are polymers of amino acids.
Proteins are very important for the body because they have many different roles. They provide structure for tissues, act as enzymes, hormones and antibodies, aid in transportation and fluid regulation.
Therefore, the correct answer is D. a polymer of amino acids.
increase in the temperature
slowing the rate of enzyme reaction
maintaining the pH
The prevention of fruits browning is the result of :
>slowing the rate of enzyme reaction
The browning of fruits can be slowed down by preventing the enzyme from working properly. Lemon juice contains an acid which can stop enzymes from working properly. For example, water and sugar in jam prevents oxygen in the air to reach enzymes and hence protects from browning.
Always keep cut fruits such as apples, pears and peaches from turning brown by coating them with an acidic juice such as lemon or orange.
The enzyme that is responsible for the browning is called polyphenol oxidase. PPO enzyme in the presence of oxygen changes substances known as phenolic compounds, through oxidation, into quinones.
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Answer:
slowing the rate of enzyme action
Explanation: