Answer:
Very toxic materials are substances that may cause significant harm or even death to an individual if even very small amounts enter the body.There are a number of very toxic materials that may be used in workplaces. Some examples include carbon monoxide, hydrogen sulfide, chlorine and sodium cyanide
Explanation:
here are generally four types of toxic entities; chemical, biological, physical and radiation: Chemical toxicants include inorganic substances such as, lead, mercury, hydrofluoric acid, and chlorine gas, and organic compounds such as methyl alcohol, most medications, and toxins.
I am pretty sure it is 4.002602
Direct Proportion and The Straight Line Graph.Straight<span> line graphs that go through the origin, like the one immediately below, show that the quantities on the graph are in direct proportion.
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cbuck763
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true. is this what you were looking for?
Answer:
- <em><u>A physical change has occurred, with no energy change.</u></em>
Explanation:
When a pencil lead is broken there is not change of any chemical properties, therefore it is not a chemical change, but just a physical change. In this case the change is just the number of pieces and dimensions.
Chemical changes always involve the formation of new different substances; the bonds between the atoms of the starting substances (reactants) breake and new bonds are formed leading to new substances (products) with different chemical composition (arrange of atoms). Chemical changes occur through chemical reactions.
Hence, if there is not change on the chemical composition, you think on physical changes. Physical changes include change in shape, size, state of matter (e.g. solid, liquid, gas). In the case of a pencil lead breaking, it is a change in shape and size.
Also, since energy has not been absorbed or released during the change, the energy of the pencil lead before having been broken is equal to the sum of the energies of the pieces of pencil lead obtained. So, this is a physical change with no energy changes.
Some examples of physical changes that include change in energy are the change of state (e.g. solid to liquid or liquid to gas) and the dissolution of a compound.
