Answer:
Hello!
Explanation:
I didn´t know if you knew, but there is no attachment. :)
Answer:
One is tension force that acts on the string and the other one is gravitational force that is acting on the pen and is therefore, the one that pulls the pen towards the ground. Therefore, the pen's motion is caused by the unbalanced force acting on the pen.
Answer : The correct option is, (B) 2, 3 and 6.
Explanation :
Combustion reaction : It is a type of reaction where a hydrocarbon react with an oxygen molecule to give carbon dioxide, water as a product.
In general,

For example : Ethane react with oxygen to give carbon dioxide and water.

In the given list,
is a reactant and
are the products.
Therefore, the correct answer is, (B) 2, 3, and 6
Ngl, there is no picture.
Answer:
pH = 7.30
Explanation:
You can find the pH using the following equation:
pH = -log[H⁺]
In this equation, [H⁺] represents the hydrogen ion concentration. You can plug the given value into the equation and solve to find the pH.
pH = -log[H⁺]
pH = -log[5 x 10⁻⁸]
pH = 7.30