Answer:
2,7 m
Explanation:
You can solve this doing an energy balance:
![m*g*h-\frac{1}{2} *m*v^{2} =41,7[J]](https://tex.z-dn.net/?f=m%2Ag%2Ah-%5Cfrac%7B1%7D%7B2%7D%20%2Am%2Av%5E%7B2%7D%20%3D41%2C7%5BJ%5D)
Solving this equation to get h:
Replacing the values and solving brings to 2,7 m
Answer:
B and C
Explanation:
When we have to do a buffer solution we always have to choose the reaction that has the <u>pKa closer to the desired pH value</u>. When we find the pKa values we will obtain:
![pKa_1=-Log[6.9x10^-^3]=2.16](https://tex.z-dn.net/?f=pKa_1%3D-Log%5B6.9x10%5E-%5E3%5D%3D2.16)
![pKa_2=-Log[6.2x10^-^8]=7.20](https://tex.z-dn.net/?f=pKa_2%3D-Log%5B6.2x10%5E-%5E8%5D%3D7.20)
![pKa_3=-Log[4.8x10^-^13]=12.31](https://tex.z-dn.net/?f=pKa_3%3D-Log%5B4.8x10%5E-%5E13%5D%3D12.31)
The closer value is pKa2 with a value of 7.2. Therefore we have to use the second reaction. In which 
is the <u>acid</u> and 
is the <u>base</u>. Therefore the answer for the first question is B and the answer for the second question is C.
Answer:
- They are highly reactive metals
- They have low electro negativity
- They have low ionization energy
- They don't exist alone in nature
- They have low densities
Explanation:
Alkali metals are the elements in group 1 of the periodic table. They include Sodium, Lithium, Potassium e.t.c.
Due to the fact they have one atom in their outermost shell, they are very unstable because they easily react with other elements and are therefore don't exist alone in nature but combined with other elements for this same reason.
Since alkali metals don't easily attract other elements due to it's lone pair in the outer most shell, it can be said to have low electro negativity.
Also, they don't need energy to discharge their electrons since they are highly reactive due to their lone pair in the outermost shell and so we say they have low ionization energy.
Due to this reason, they also have low densities.
Answer:
the abundance of non-native plants. this MAY be right.
Explanation:
i thought it would be an increase in pollution.
Answer:
B. abiotic
Explanation:
in biology and ecology, abiotic components or abiotic factors are non living chemical and physical parts of the environment that affect living organisms and the functioning of ecosystems.
