Answer:
Common sources of error include instrumental, environmental, procedural, and human. All of these errors can be either random or systematic depending on how they affect the results. Instrumental error happens when the instruments being used are inaccurate, such as a balance that does not work (SF Fig
Explanation:
An organism that obtains energy and nutrients by feeding on other organisms or their remains. A food web is a model of the feeding relationships between many different consumers and producers in an ecosystem. Without plants (the primary producers) consumers and decomposers would not be able to live. Producers always start every food chain. A consumer, also called a heterotroph, is an organism that cannot make its own food. It must eat producers or other organisms for energy.
Answer:
C. CH4 + 202 – CO2 + 2H20
Explanation:
CH4+O2-CO2+H20
The above equation represents combustion of methane to produce carbon-dioxide and water.
One carbon atom is present on the reactant side as well as on the product side. Four hydrogen atoms are present on the reactant side and two hydrogen atoms on product side. In order to balance this equation, we would multiply water molecule by two. Now there are four atoms of oxygen in the product side but only two on reactant side, so we will multiply oxygen molecule by two on the reactant side. Now the equation is balanced.
The balanced chemical equation is:
CH4+202-CO2+2H2O
This equation obeys the law of conservation of mass as the mass of the reactants is same as that of the products.
Typically you use experimental and control groups in an experiment. a control group is like the default, and the experimental is the one you actually experiment with.
for example if i run an experiment on the effects of food dye on a leaf stem, i’ll have my control group (the ones without food dye) to compare to the experimental group (the ones with food dye)
the control group is a way for scientists to see how an experiment truly affected or altered the subject
