12 times breathe give 240 ml of pure 
. Each breathe gives 20 ml of .
Let us consider, volume of air per breathe= x ml.
Pure from inhaled air= 
ml and Pure from exhaled air= 
ml.
Pure from inhaled and exhaled air= 20 ml
So, + = 20
Therefore, x = 55.5 ml
So, volume of air per breath= 55.5 ml.
Answer: 8.2
Explanation:
pH of a solution is - Log [ H+].
pH = - Log [ 6.2 x 10-9 M]
= 9 - 0.7924
pH = 8.24 approx 8.2
Cruising at 35,000 feet in an airliner, straight toward the east,
at 500 miles per hour.
Since your speed is not changing and you're moving in a straight line,
your acceleration is zero.
Answer:
20 amu
Explanation:
An atom consist of electron, protons and neutrons. Protons and neutrons are present with in nucleus while the electrons are present out side the nucleus.
All these three subatomic particles construct an atom. A neutral atom have equal number of proton and electron. In other words we can say that negative and positive charges are equal in magnitude and cancel the each other. For example if neutral atom has 6 protons than it must have 6 electrons. The sum of neutrons and protons is the mass number of an atom while the number of protons are number of electrons is the atomic number of an atom.
Atomic mass = Number of protons + number of neutrons
Atomic number = Number of electrons or number of protons.
In given question it is stated that atom has 11 electrons and -1 charge it means this atom has 12 electrons in neutral state.
Thus it has 12 protons because number of electrons and protons are always equal.
Atomic mass of given atom:
Atomic mass = Number of protons + number of neutrons
Atomic mass = 12 + 8 = 20 amu
Answer:
option C = 9.0 x 10²³ atoms
Explanation:
Data Given:
no. of moles of tin (Sn) atoms = 1.5 moles
no. of tin (Sn) atoms = ?
Solution:
Formula used to find number of atoms
no. of moles = no. of atoms / Avogadro's number
Rearrange the above equation:
no. of atoms = no. of moles x Avogadro's number . . . . . . (1)
Where
Avogadro's number = 6.022 x 10²³
Put values in equation 1
no. of atoms = 1.5 x 6.022 x 10²³
no. of atoms = 9.033 x 10²³
Round the figure = 9.0 x 10²³ atoms
So option C is correct
