Answer:
Average Molar mass is 114.8u
Explanation:
» From the formula of average Relative Atomic Mass [ RAM ]
» We have two isotopes of Indium,
- Indium-113, mass » 112.9u, % » 4.28%
- Indium-115, mass » 114.9u, % » 95.72%
Answer:
The given metal is beryllium.
Explanation:
Given data:
Mass of metal = 74 g
Volume of metal = 40 cm³
Which metal is this = ?
Solution:
First of all we will calculate the density.
it is mass divided by volume.
d = m/v
d = 74 g/40 cm³
d = 1.85 g/cm³
In literature it is given that the density of beryllium is 1.85 g/cm³. Thus given metal is beryllium.
Answer:
option A= Physical change
Explanation:
physical change:
" It is a change in which no new substance is formed"
Breaking of object like glass is the example of physical change because it is not change into another object. It effect the form of object but can not change the chemical composition.
Chemical changes:
" it is a change in which one substance is converted into new product through chemical reaction".
During the chemical changes the types and the number of atom remain same but their arrangement changed.
for example: burning of wood, baking of cake, digesting food, resting of iron etc.
Physical reaction:
" physical reaction occur during the molecular rearrangement. There is no chemical change occur"
In this type of changes no bonds are break to form new bonds, for example boiling point.
Chemical reaction:
" chemical reaction occur when molecules are chemically react with each others and bonds formation and breaking is also occur"
Answer:
C. Unbalanced
Explanation:
A force which can change the state of an object by changing it's speed, position or direction of motion is known as an unbalanced force. It is the resultant of all forces which are acting on a body and causing a change in the state of rest of motion of the body.
Assume a box is resting on the floor. The forces acting on the box in the rest are Normal (by the ground on the box) in upward direction and gravitational force Mg (due to gravity). Although these two forces are acting on the box, it is still in rest because these forces are balanced to each other. When we pull or push the box by applying appropriate force, the box will start to move because the force applied by us is unbalanced and there is no any force in the opposite direction to make this force balanced.
