Answer:
1 mole
Explanation:
A mole of water molecules contains 2 moles of hydrogen atoms and 1 mole of oxygen atoms.
<u>Answer:</u> When an atom is an ion, it must have a charge.
<u>Explanation:</u>
An ion is formed when a neutral atom looses or gains electrons.
- When an atom looses electrons, it results in the formation of positive ion known as cation. <u>For Example:</u> Sodium looses 1 electron to form ion.
- When an atom gains electrons, it results in the formation of negative ion known as anion. <u>For Example:</u> Chlorine gains 1 electron to form ion.
Hence, when an atom is an ion, it must have a charge.
Explanation:
Given that,
Mass number, A = 302
Atomic number, Z = 119
We know that, atomic number = no of protons
Protons = 119
Mass no. = No. of neutrons + No. of protons
302 = No. of neutrons + 119
No. of neutrons = 302 - 119
= 183
No. of electrons = No. of protons
= 119
To solve this, we can use two equations.
t1/2 = ln 2 / λ = 0.693 / λ - (1)
where, t1/2 is half-life and λ is the decay constant.
Nt = Nοe∧(-λt) - (2)
Nt = amount of atoms at t =t time
Nο = initial amount of atom
t = time taken
From (1),
10 yr = 0.693 / λ
λ = 0.693 / 10 yr
From (2)
Nt = 100 g eΛ(-(0.693 / 10 yr) x 20 yr)
Nt = 25.00 g.
Hence, remaining mass will be 25.00 g