1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
vladimir1956 [14]
4 years ago
15

What is the controlled variable for: 1.Does the amount of leaves on a tree affect how many birds build their nests in it? 2.Does

the acid level of the lake affect how many fish live there?
Chemistry
1 answer:
zhuklara [117]4 years ago
3 0

Answer:

Case I - Number of leaves

Case II - Acid level of lake

Explanation:

A controlled variable is the one which is kept constant or unchanged  throughout an experiment.  

In the question –  

For case I –  

Here the impact of number of leaves on a given tree is studied on the number of nest build by birds.  

Thus, the number of leaves is a constant variable that shall remain constant throughout and hence it is a controlled variable.  

For case II –  

Just like in the above case, in this case too the acid level of the lake shall remain constant as the effect of acid level of lake is studied on the survival instinct of fishes in the lake.  

You might be interested in
two perfumes A and B were released at the same time and you are standing 7.5metres away from both of them.molarmass of perfume A
kifflom [539]

17.40 sec is the time will take to smell second perfume after diffusion takes place

Acc. to Graham's law of Diffusion

Diffusion of Gas inversely proportional to square root of its Molecular mass.

<u>rb (Perfume B)</u>

ra(perfume A)

= \sqrt{\frac{Ma}{Mb} } its equation (1)

Give molar mass of Perfume A = 275 g/mol

molar mass of Perfume B= 205g/mol putting value in (1)

» \frac{rb}{ra}=\sqrt{\frac{275}{205} }

\frac{rb}{ra} =1.16<em> its eq (2)</em>

» Perfume B will defuse 1:16 times faster than perfume A.

Hence, perfume B will be first smelled by Person.

Sf Equal volume V of two goes diffuse in t1 and t2 sec. respectively ton

\frac{ra}{rb}=\frac{tb}{ta}

Now,, from eq(2) toto

1/1:15 = \frac{tb}{ta}

ta

Given tb =the smell of Perfume B as it diffuse faster  

ta= 1.15 x 15 see  

=ta2=17.40 sec

Learn more about diffuse here

brainly.com/question/3266850

#SPJ9

4 0
1 year ago
The elements most likely to form more than type of ion are the....
emmainna [20.7K]
The elements most likely to form more than one type of ion are thetransition metals
7 0
3 years ago
Read 2 more answers
Which of the following, in the solid state, would be an example of a metallic crystal?
e-lub [12.9K]
Iron because it is formed by metal atoms.
7 0
2 years ago
Which statement best explains the purpose of using a mole in the measurement of matter?
oee [108]
Mole is a unit that has become the way of scientist and those who are interested in the filed to count the number of substances or atoms. Thus, the answer is letter B. It will be very impractical for them to count the atoms using the natural numbers are they are very small and very numerous. 
8 0
4 years ago
Read 2 more answers
An element 'X after reacting with acids liberates hydrogen gas and candisplace lead and mercury from their salt solutions. The m
adell [148]

The element X is Copper.

Explanation :

Reactive metals from 3d transition series like Cu are very reactive because their standard reduction potential values are low.

Hence, when treated with a acid it tends to liberate hydrogen gas.

Also, because of  its low reduction potential value, it can easily displace lead and tin from their salt solutions.

Learn more :

https://brainly.in/question/6679934

5 0
3 years ago
Other questions:
  • Determine the mass in grams of each of the following:
    8·1 answer
  • Since the number of atoms in a substance is so large , a unit to count them was created. This unit is the number of atoms in 12
    12·2 answers
  • What happens when the threat of exposure to dirty air is reduced in a community?
    7·2 answers
  • What mass (g) of ammonium acetate contains 8.334 x 1024 hydrogen atoms?
    11·1 answer
  • Be sure to answer all parts. Nitric oxide, NO·, is a radical thought to cause ozone destruction by a mechanism similar to that o
    12·1 answer
  • Is anyone else's brainly not working or is mine the only one that is tweaking?
    6·1 answer
  • El suero fisiológico tiene una concentración de 8,78 gr/lt. Calcula la masa de NaCl que ingresa en el organismo de un paciente a
    12·1 answer
  • What type of subatomic particles are found in the cloud?
    10·1 answer
  • Describe two ways nitrogen gas is changed into forms that living things<br> can use
    14·2 answers
  • What is the name of the molecule below
    9·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!