Explanation:
The half-life is the time taken for a radioactive substance to decay to half of its original composition.
Let us assume that the original amount is x atoms;
Half - life = 60days
Days Composition Half-life number
0 x 0
60 x/2 1
120 x/4 2
180 x/8 3
240 x/16 4
300 x/32 5
360 x/64 6
The fraction that would be left after 360 days will be
Answer:
C) solid, liquid, gas
Explanation:
Which grouping shows a decrease in Intermolecular
Forces of Attraction?
A) gas, liquid, solid B) liquid, solid, gas
C) solid, liquid, gas D) solid, gas, liquid
the further the particles are from each other, the less the intermolecular attraction they are farthest in a gas, then a liquid, and closest in a solid
Answer:
7.5 × 10¹⁵ Hz
Explanation:
Given data
- Wavelength of the radio waves (λ): 40 nm = 40 × 10⁻⁹ m = 4.0 × 10⁻⁸ m
- Frequency of the radio waves (ν): ?
- Speed of light (c): 3.00 × 10⁸ m/s
We can determine the frequency of the radio waves using the following expression.
c = λ × ν
ν = c/λ
ν = (3.00 × 10⁸ m/s)/4.0 × 10⁻⁸ m
ν = 7.5 × 10¹⁵ s⁻¹ = 7.5 × 10¹⁵ Hz
The elements are electrically neutral, this is they have the same amount of positive as negative charge.
Electrons and protons have each the same amount of charge but different sign. Eletrons are negative and protons are positive.
Then to be neutral, the number of electrons must be equal to the number of protons. This mean that the element must have 12 electrons.
Answer: 12.