They should identify the confounding variable.
Some condition that is not examined by the scientist might alter the experiment result. That condition is called confounding variable. If the method of the experiment same but result is very different, there should be unidentified confounding variable. It could be air humidity, temperature, ventilation, light, time of the year or anything that might not be seen by naked eye.
Try to redo the experiment with controlling variable as much as possible.
Answer:
A. cycas
1. it is thick and scaly
2. it grow relatively slowly and have a large, terminal rosette of leaves.
B. bamboo
1. it is very durable
2. it is both flexible and elastic
C. lemna
1. it grows as simple free-floating thalli on or just beneath the water surface
2. it are small, not exceeding 5 mm in length
D. paddy
1. it is variety purity
2. it degree of purity
E. sugarcane
1. it is bear long sword-shaped leaves
2. it's stalks are composed of many segments, and in each joint there is a bud
Explanation:
The scientists used the term electromagnetic spectrum to describe the entire range of light that exists in the universe. From gamma rays to radio waves, most of the light present in the universe invisible to us.
The electromagnetic spectrum describes all the wavelengths of light. It explores an otherwise invisible universe, from an exploding stars to the dark nebulae.
The electromagnetic spectrum that consists of radio waves (used in commercial television and radios, radar, microwaves ), infrared radiation, visible light, gamma rays, x-rays and ultraviolet radiation rays. All the wavelengths and frequencies of the electromagnetic spectrum is used in spectroscopy.
The balanced equation is
4Fe+3O₂⇒2Fe₂O₃
We know that the mole of Fe₂O₃ is 6, and since the ratio between oxygen and <span>Fe₂O₃ is 3:2, we can see that
3:2 = x:6 (3 oxygen moles can make 2 </span>Fe₂O₃ moles = x oxygen moles can make 6 <span>Fe₂O₃ moles)
</span><span>
Multiply outside and inside (3*6 , 2*x) and put them on opposing sides of the equation
2*x = 3*6
2x=18
x=9
Therefore 9 moles of oxygen is needed.
</span>
