<em>Answer</em><em>:</em><em> </em><em>What</em><em> </em><em>does</em><em> </em><em>a</em><em> </em><em>duck</em><em> </em><em>eat</em><em> </em><em>most</em><em> </em><em>often</em><em>?</em>
<em>Option</em><em> </em><em>D</em><em> </em><em>is</em><em> </em><em>the</em><em> </em><em>best</em><em> </em><em>scientifi</em><em>c</em><em> </em><em>ques</em><em>tion</em>
<em>Hope</em><em> </em><em>it</em><em> </em><em>helps.</em><em>.</em><em>.</em><em>.</em>
Answer:
Chlorine
Explanation:
Each arrow represents one electron. Most of the boxes are filled, meaning they have two electrons. The last box only has one arrow, so it only has one electron. If you add it up, you get 17, which is Chlorine.
Answer:
The two main types of bonds formed between atoms are ionic bonds and covalent bonds.
Explanation:
An ionic bond is formed when one atom accepts or donates one or more of its valence electrons to another atom. A covalent bond is formed when atoms share valence electrons.
Answer:
Can I get my 50 points now?
Explanation:
The helium is formed during the natural radioactive decay of elements such as uranium and thorium. These heavy elements were formed before the earth but they are not stable and very slowly, they decay. One mode of decay for uranium is to emit an alpha-particle.
Answer:
2.2 % and 0 %
Explanation:
The equation we will be using to solve this question is:
N/N₀ = e⁻λ t
where N₀ : Number of paricles at t= 0
N= Number of particles after time t
λ= Radioactive decay constant
e= Euler´s constant
We are not given λ , but it can be determined from the half life with the equation:
λ = 0.693 / t 1/2 where t 1/2 is the half-life
Substituting our values:
λ = 0.693 / 55 s = 0.0126/s
a) For t = 5 min = 300 s
N / N₀ = e^-(0.0126/s x 300 s) = e^-3.8 = 0.022 = 2.2 %
b) For t = 1 hr = 3600 s
N / N₀ = e^-(0.0126/s x 3600 s) = 2.9 x 10 ⁻²⁰ = 0 % (For all practical purposes)
