The breaking and making of chemical bonds can explain chemical reactions and energy flow. a. True b. False
True
(2) They differ in their properties, only.
(3) They differ in their molecular structure and properties.
(4) They do not differ in their molecular structure or properties.
Answer: Option (3) is the correct answer.
Explanation:
When an element exists in two or more different physical forms then they are known as allotropes.
For example, diamond and graphite are both allotropes of carbon.
In graphite, carbon atoms are joined together in sheets of six sided lattice. Whereas in diamond, carbon atoms are joined together in four cornered lattice.
Therefore, as these allotropes are made up of same element so they have similar chemical properties but different physical properties like melting point, boiling point etc.
Also, both of them have different molecular structure.
Thus, we can conclude that the statement the differ in their molecular structure and properties correctly describes diamond and graphite.
Carbon disulfide is formed by a direct reaction of carbon and sulfur. At room temperature, CS2 is a colorless liquid with an offensive odor. Carbon disulfide vapors are flammable.
59 Identify one physical property and one chemical property of CS2. [1]
Answer: Physical property of is state of matter (liquid) and it is a chemical compound.
Explanation:
Chemical property is defined as the property of a substance which is observed during a reaction where the chemical composition identity of the substance gets changed.
Physical property is defined as the property which can be measured and whose value describes the state of physical system. For Example: State, density etc.
Carbon disulfide is the compound which is formed by the chemical combination of carbon and sulfur atoms. The equation for this follows:
The chemical property of carbon disulfide is different from that of carbon and sulfur. Thus, this is a chemical compound.
It is given, that this compound is a colorless liquid, which means that the state of this compound is liquid state.
Hence, physical property of is state of matter (liquid) and it is a chemical compound.
The physical property of carbon disulfide is that at room temperature, CS2 is a colorless liquid with an offensive odor. The chemical property of carbon disulfide is that it is formed by a direct reaction of carbon and sulfur.
B. MgO
C. CaO
D. SrO
Answer: BeO
Explanation:
percent by mass of oxygen
percent by mass of oxygen in BeO
percent by mass of oxygen in MgO
percent by mass of oxygen in CaO
percent by mass of oxygen in SrO