Because the number of valence electrons of an element determines the properties and in particular the reactivity of that element.
In fact, elements of the first group (i.e. only one valence electron) have high reactivity, because they can easily give away their valence electron to atoms of other elements forming bonds. On the contrary, elements of the 8th group (noble gases) have their outermost shell completely filled with electrons, so they do not have valence electrons, and they have little or no reactivity at all.
Answer:
an increase in gasses that absorb heat
Explanation:
Greenhouse effect refers to the gradual increase in the earth's temperature due to an increase in the concentration of certain gases in the atmosphere. These gases are called greenhouse gases and they include; water vapour, nitrogen 1 oxide, carbon IV oxide etc. Green house effect is said to occur when heat radiating outwards from the earth surface towards space is trapped close to the earth's surface due to the presence of greenhouse gases in the atmosphere.
Greenhouse effect leads to increase in the temperature of the earth, melting of polar ice caps and possibly flooding due to a rise in sea levels.
Greenhouse gases act as glass in a greenhouse. They allow heat to pass through onto the earth surface but trap the heat and prevent it from being radiated outwards back to space. Thereby increasing the surface temperature of the earth.
Answer:
A
Explanation:
It would not be C because prokaryotic cells don't have a nucleus. And if you're looking for a body in the cell that controls the nutrients and water it would be A.
Answer:
1. The period is 1.74 s.
2. The frequency is 0.57 Hz
Explanation:
1. Determination of the the period.
Spring constant (K) = 30 N/m
Mass (m) = 2.3 Kg
Pi (π) = 3.14
Period (T) =?
The period of the vibration can be obtained as follow:
T = 2π√(m/K)
T = 2 × 3.14 × √(2.3 / 30)
T = 6.28 × √(2.3 / 30)
T = 1.74 s
Thus, the period of the vibration is 1.74 s.
2. Determination of the frequency.
Period (T) = 1.74 s
Frequency (f) =?
The frequency of the vibration can be obtained as follow:
f = 1/T
f = 1/1.74
f = 0.57 Hz
Thus, the frequency of the vibration is 0.57 Hz
Answer:
The new separation distance between adjacent bright fringes will be <u>4 mm</u>
Explanation:
Since, the distance between adjacent bright fringes is given by the formula:
Δx₁ = λL/d = 2 mm -------- eqn (1)
where,
Δx = Distance between adjacent bright fringes
λ = wavelength of light = constant for both cases
L = Distance between the slits and the screen
d = slit separation
Now, for the second case:
Slit Separation = d/2
Therefore,
Δx₂ = λL/(d/2)
Δx₂ = 2(λL/d)
using eqn (1), we get:
Δx₂ = 2 Δx₁
Δx₂ = 2(2 mm)
<u>Δx₂ = 4 mm</u>
