He is missing a (real) control. Growing two plants without plant food at all doesn't count; in order to see if the new food is better, he must also grow plants with the original food in order to compare it.
He does have an independent variable. This is the type of plant food. It's independent because he has direct control over it.
He needs to give plants the same conditions besides food: same water (amount), same light exposure, same temperature, etc.
He needs to choose a quantitative way to measure how much the plants grew, like mass or length.
Urricanes<span> act as giant heat engines, so it is logical to assume that an </span>increase<span> in sea surface temperatures (SSTs) will make more intense </span>hurricanes<span>. Indeed, there is a general consensus among </span>hurricane<span> scientists that an </span>increase<span> in SSTs due to global warming, should, in theory, lead to more intense </span>hurricanes<span>.</span>As the storm gets stronger, it gets rounder and the eye begins to form. Really stronghurricanes<span> have very clear round eyes like the one in this picture. The most intense winds in a </span>hurricane are in the thunderstorms that form the eyewall. Tropical cyclones strengthen when all of the conditions are right for them.
Answer:
only columns
Explanation:
All atoms of elements present in same group or column having same number of valance electrons. Thus the elements in same group having same properties.
For example:
Consider the second group. It consist of alkaline earth metals. There are six elements in second group. Beryllium, magnesium, calcium, strontium, barium and radium.
All have two valance electrons.
Electronic configuration of Beryllium:
Be = [He] 2s²
Electronic configuration of magnesium.
Mg = [Ne] 3s²
Electronic configuration of calcium.
Ca = [Ar] 4s²
Electronic configuration of strontium.
Sr = [Kr] 5s²
Electronic configuration of barium.
Ba = [Xe] 6s²
Electronic configuration of radium.
Ra = [ Rn] 7s²
They are present in group two and have same number of valance electrons (two valance electrons) and show similar reactivity.
They react with oxygen and form oxide.
2Ba + O₂ → 2BaO
2Mg + O₂ → 2MgO
2Ca + O₂ → 2CaO
this oxide form hydroxide when react with water,
BaO + H₂O → Ba(OH)₂
MgO + H₂O → Mg(OH)₂
CaO + H₂O → Ca(OH)₂
With sulfur,
Mg + S → MgS
Ca + S → CaS
Ba + S → BaS
Answer:
k = 100 mol⁻² L² s⁻¹, r= k[A][B]²
Explanation:
A + B + C --> D
[A] [B] [C] IRR
0.20 0.10 0.40 .20
0.40 0.20 0.20 1.60
0.20 0.10 0.20 .20
0.20 0.20 0.20 .80
Comparing the third and fourth reaction, the concentrations of A and C are constant. Doubling the concentration of B causes a change in the rate of the reaction by a factor of 4.
This means the rate of reaction is second order with respect to B.
Comparing reactions 2 and 3, the concentrations of B and C are constant. Halving the concentration of A causes a change in the rate of the reaction by a factor of 2.
This means the rate of reaction is first order with respect to A.
Comparing reactions 1 and 3, the concentrations of A and B are constant. Halving the concentration of A causes no change in the rate of the reaction.
This means the rate of reaction is zero order with respect to C.
The rate expression for this reaction is given as;
r = k [A]¹[B]²[C]⁰
r= k[A][B]²
In order to obtain the value of the rate constant, let's work with the first reaction.
r = 0.20
[A] = 0.20 [B] = 0.10
k = r / [A][B]²
k = 0.20 / (0.20)(0.10)²
k = 100 mol⁻² L² s⁻¹
Answer:trifluoromethanesulfonic acid (CF3SO3H).
Explanation:
The trifluoromethanesulfonic acid (CF3SO3H) has a halogen atom which stabilizes the leaving group by withdrawal of charge from the SO3- moiety. The methanesulfonic acid (CH3SO3H) contains an electron pushing group which tends to destabilize the charge centre. The better leaving group will be the stabilized anion which in this case is trifluoromethanesulfonic acid (CF3SO3H). This typifies the role of stabilizing factors in formation of chemical species.
