Answer:
A. a new substance is being produced.
Explanation:
The bubbles most likely indicates that a new substance is being produced by this reaction. In essence, we describe this sort of change as chemical change.
In a chemical change, new substances are usually produced. They are accompanied by the evolution or absorption of energy.
The reaction of Zinc with a strong acid to produce bubbles on the surface of the metal indicates a chemical change and the formation of a new kind of substance.
Take for example, let zinc reacts with hydrocholoric acid, HCl;
Zn + 2HCl → ZnCl₂ + H₂
Since Zn is higher than Hydrogen in the activity series, it will displace it from HCl and liberate hydrogen gas as a product. This will cause the bubbles observed in the reaction.
This is a chemical change and new products have been formed.
B and D are wrong because they are both physical changes.
C is wrong because no information about such is provided by the problem statement.
So, when a piece of zinc metal combines with a strong acid, a new kind of substance is produced.
Answer:
Here are three examples
Explanation:
In a reversible reaction, the conversions of reactants to products and of products to reactants occur at the same time.
Example 1
The reaction of hydrogen and iodine to from hydrogen iodide.
H₂ + I₂ ⇌ 2HI
Example 2
The dissociation of carbonic acid in water to form hydronium and hydrogen carbonate ions
H₂CO₃ + H₂O ⇌ H₃O⁺ + HCO₃⁻
Example 3
The dissociation of dinitrogen tetroxide to nitrogen dioxide.
N₂O₄ ⇌ 2NO₂
Woven fabric is any textile formed by weaving. Woven fabrics are often created on a loom, and made of many threads woven on a warp and a weft. Technically, a woven fabric is any fabric made by interlacing two or more threads at right angles to one another.
Answer:
hello your question is incomplete below is the missing part of the question
answer : 104°c
Explanation:
The Eutectic temperature for the mixture is 104°c
From the chart attached below it can be seen that the temperature from the two lines of best fit cross is 104°c
The moving car experiences unbalanced forces when applying brakes; when a car is slowing as it reaches a stop light.
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Explanation:
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When the car driver applies brakes to a car in order to stop, an unbalanced force is applied to the car. The speed of car gradually reduces and there’s a decrease in acceleration; a net force acts on it.
Options A and D has a box and a rocket always in a rest position. A car with cruise control is an adaptable speed setting for a vehicle which helps it to maintain a fairly constant speed. Constant velocity gives zero acceleration and hence no considerable unbalanced forces appear.
