All matter is made of particles; these can be single atoms or atoms chemically joined to make molecules. Using this fact, matter can be classified into three broad groups: elements, compounds and mixtures. In an element, all the atoms are of the same type. If more than one type of atom is chemically joined, then a compound has been formed. If more than one type of atom or molecule is contained in the same substance, and the particles aren't chemically joined, this is a mixture.
Answer:
0.80865 Hz
1.23662 seconds
Explanation:
g = Acceleration due to gravity = 9.81 m/s²
l = Length of arm = 0.57 m
Length of simple pendulum is given by

The frequency is given by

The frequency is 0.80865 Hz
The time period is given by

The time period is 1.23662 seconds
You first find the mass and the volume of that object. Then you divide mass ÷ volume