C. Magma from venus mantle erupted as lava.
Explanation:
A volcano is a land form which results from the eruption of molten rocks (lava) on the surface. Volcanic rocks are a special type of igneous rock that forms when molten rock cools and solidifies on the surface.
For a planet like Venus which is presently not active and little to no movement occurs within the plates, the volcanisim must have occurred when the planet was relatively young and it must have been millions of years ago.
It is widely believed that Venus was geologically active in times past. Mantle generated lava must have solidified on the surface in times past to have formed the volcano.
Evaluating other options:
Impact of space objects on Venus would lead to the formation of a crater which is a depression on the surface. The rock would be mostly metamorphic.
If water was ever present in Venus, they would have produced sedimentary rocks instead. The erosive power of water is not high enough to cut through the crust. Also, water would not aid the formation of volcanoes.
Heat is not enough to from volcanoes. Other factors are also in play.
Answer:
2.79 mg iron-59 is left in the sample after 267 days.
Explanation:
Given that:
Half life = 44.5 days
Where, k is rate constant
So,
The rate constant, k = 0.0156 days⁻¹
Using integrated rate law for first order kinetics as:
![[A_t]=[A_0]e^{-kt}](https://tex.z-dn.net/?f=%5BA_t%5D%3D%5BA_0%5De%5E%7B-kt%7D)
Where,
![[A_t]](https://tex.z-dn.net/?f=%5BA_t%5D)
is the concentration at time t
![[A_0]](https://tex.z-dn.net/?f=%5BA_0%5D)
is the initial concentration = 180 mg
Time = 267 days
So,
![[A_t]=180\ mg\times e^{-0.0156\times 267}](https://tex.z-dn.net/?f=%5BA_t%5D%3D180%5C%20mg%5Ctimes%20e%5E%7B-0.0156%5Ctimes%20267%7D)
![[A_t]=180\times e^{-0.0156\times 267}\ mg](https://tex.z-dn.net/?f=%5BA_t%5D%3D180%5Ctimes%20e%5E%7B-0.0156%5Ctimes%20267%7D%5C%20mg)
![[A_t]=2.79\ mg](https://tex.z-dn.net/?f=%5BA_t%5D%3D2.79%5C%20mg)
<u>2.79 mg iron-59 is left in the sample after 267 days.</u>
KOH <span> + HC</span>₂<span>H</span>₃<span>O</span>₂<span> = H</span>₂<span>O + KC</span>₂<span>H</span>₃<span>O</span><span>₂
hope this helps!</span>
Answer:
number of valence electrons
Explanation:
The chemical properties of the atoms of elements in a group of the periodic table is most closely related to the number of valence electrons. All the chemical properties can be justified just by the number of valence electrons.
