C. The mass number is the amount of Protons and electrons there are combined, so 200 - 80 is 120.
Pan 4: theyre the smallest and most broken down :)
Answer: The correct option is 2.
Explanation: Polyatomic ions are defined as the ions in which two or more elements are covalently bonded to act as a single unit. They always carry some charge.
Examples of polyatomic ions are:
known as hydroxide ion,
known as sulfate ion
We are given a compound
having 2 ions which are
and
. these ions are named as sodium ions and hydrogen carbonate ions.
Therefore, the correct option is 2.
Answer:
Kinetic energy is directly proportional to mass
Explanation:
Kinetic energy is directly proportional to the mass of an object and also directly proportional to the square of the velocity of that object:

Notice that if we keep velocity constant and only increase the mass of a object, the kinetic energy of that object would increase, as we've already emphasized the direct relationship between the kinetic energy term and the mass term.
Let's take a simple example: assume that object 1 and object 2 are both moving at the same velocity but object 1 has a much lower mass than object 2. According to the equation, object 1 has lower kinetic energy. This object can then transform all of its kinetic energy into some other form, say, heat the ground. The heat transferred will be significantly lower than by the object 2 moving at the same velocity but having a much greater mass.