Answer:
True. A gas does not have a definite volume. Therefore, making this statement correct.
Explanation:
true
true
False
It is the fingerprint of all of the colors of light emitted by a star.
It is a graph of all the pollution given off by a star.
It is a graph of the star’s solar flares.
(2) A has a high melting point, and B has a low melting point.
(3) A dissolves in water, and B does not dissolve in water.
(4) A does not burn in air, and B does burn in air.
The correct option is 4.
The ability of a compound to burn in air is a chemical property and can be used to distinguish between two compounds.
The statement that describes a chemical property which can be used to distinguish between compound A and compound B is: (4) A does not burn in air, and B does burn in air. Physical properties like color, melting point, and solubility (options 1, 2, and 3) are characteristics that can be observed without changing the substance into another substance. On the other hand, a chemical property describes how a substance interacts with other substances, including its flammability. Therefore, the ability or inability of a compound to burn in air would be a chemical property.
#SPJ3
b. a compound is decomposed by an electric current.
c. a compound burns in the presence of oxygen.
d. a new compound is formed.
Answer: d. a new compound is formed.
Explanation:
1. Decomposition is a type of chemical reaction in which one reactant gives two or more than two products.
Example:
2. Electrolytic decomposition is a type of chemical reaction in which one reactant gives two or more than two products. on passing electric current.
Example:
3. Combustion is a type of chemical reaction in which fuel is reacted with oxygen to form carbon dioxide and water.
Example:
4. Synthesis reaction is a chemical reaction in which two reactants are combining to form one product.
Example:
Natural systems like water in a pond rarely reach thermal equilibrium due to temperature differences and energy transfer limitations.
Natural systems like the water in a pond rarely reach thermal equilibrium due to various factors.
These factors prevent the pond from reaching thermal equilibrium.
#SPJ1
B) Water would be able to dissolve all ionic compounds.
C) Water would not expand when it freezes.
D) Water would not exist on Earth.
The hydrogen bond is a secondary bond formed between a hydrogen (attached to an highly electronegative element ,: F, O or N) and another atom of an highly electronegative element ,: F, O or N.
In case of water hydrogen bond helps water
a) to dissolve certain substances which can make hydrogen bond
b) it makes it liquid and room temperature unlike H2S which is a gas at room temperature due to absence of hydrogen bond
c) higher volume and low density of ice as compared to liquid water. Due to hydrogen bond ice forms open cage like structure which increases its volume and decreases its density. Thus water expands on freezing
So in absence of hydrogen bond Water would not expand when it freezes.