The first one is 2
The second is 1
The third is 6
And the fourth is 3
Answer:
Explanation:
<u>1) Data:</u>
a) [OH⁻] = 2.1 × 10⁻⁶ M . . . (the symbol g shown in the question is a typo)
b) pH = ?
<u>2) Formulae:</u>
<u>3) Solution:</u>
- pOH = log ( 1 / 2.1 × 10⁻⁶ ) = 5.7
- pH = 14 - pOH = 14 - 5.7 = 8.3
Hello there.
<span>3. atom
</span>found in molecules
All correct except last option because instantaneous change in acceleration does not change the velocity.
The number of electrons in a neutral atom is equal to the number of protons. The mass number of the atom (M) is equal to the sum of the number of protons and neutrons in the nucleus. The number of neutrons is equal to the difference between the mass number of the atom (M) and the atomic number (Z).
Protons and neutrons are in the center of the atom, making up the nucleus. Electrons surround the nucleus. Protons have a positive charge.
Each element has a specific mass number and a specific atomic number. These two numbers are fixed for an element. The mass number tells us the number (the sum of nucleons) of protons and neutrons in the nucleus of an atom. it has mass number 235 , it means that the sum of neutrons and protons in a carbon atom is 235.3
