Answer:
3600 kg
Explanation:
From the question,
Density = Mass/Volume
D = M/V.............................. Equation 1
Where D = Density of the substance, M = mass of the substance, V = Volume of the subtance.
Make M the subject of the equation
M = D×V ............................ Equation 2
Given: D = 1200 kg/m³, V = 3 m³.
Substitute these values into equation 2
M = 1200×3
M = 3600 kg.
Hence the mass of the substance is 3600 kg
Answer: The intensity level of sound in the bedroom is 80dB
Explanation:
Intensity of lawn mower at r=1m is 100dB
Beta1= 10dBlog(I1/Io)
100dB= 10dB log(I1/Io)
10^10= I1/Io
I1= Io(10^10)
10^12)×(10^10)= I1
I1=10^-2w/m^2
Intensity of lawn mower at r=20m
I2/I1=(r1/r2)^2 =(1/20)^2
I2= I1(1/400)
I2=2.5×10^-3W_m^2
Intensity of 4 lown mowers at 20m fro. Window
= 10dBlog(4I2/Io)
= 10^-4/10^-12
=80dB
Answer:
atom -
the smallest particle of a chemical element that can exist.
atomic mass-
the quantity of matter contained in an atom of an element
atomic weight -
ratio of the average mass of a chemical element's atoms to some standard
protons-
stable subatomic particle that has a positive charge equal in magnitude to a unit of electron charge and a rest mass of 1.67262 × 10−27 kg
electrons-
a stable subatomic particle with a charge of negative electricity, found in all atoms and acting as the primary carrier of electricity in solids
neutrons-
a subatomic particle of about the same mass as a proton but without an electric charge, present in all atomic nuclei except those of ordinary hydrogen.
energy levels-
one of the stable states of constant energy that may be assumed by a physical system
[used especially of the quantum states of electrons in atoms and of nuclei. — called also energy state.]
Covalent bonds
the interatomic linkage that results from the sharing of an electron pair between two atoms.
ionic bonds
type of linkage formed from the electrostatic attraction between oppositely charged ions in a chemical compound.
Valence electrons
a single electron or one of two or more electrons in the outer shell of an atom that is responsible for the chemical properties of the atom.
Lewis Dot Diagram
A way of representing atoms or molecules by showing electrons as dots surrounding the element symbol. One bond is represented as two electrons.