How many lithium atoms are in 4.5 moles of Li?

Answer;

A. Bias

If the personal opinion of a scientist affects the way that the experimental results are reported, that is called bias.

Explanation;

-An experimenter bias, is a process where the scientists performing the research influence the results, in order to portray a certain outcome.

-Bias is among the factors that makes a qualitative research much more dependent upon experience and judgment than quantitative research.

-Bias in a research may arise from experimental errors and failure to consider all the possible variables and also when the researchers select the subjects that are more likely to generate the desired results.

Hi,

Here is the step by step procedure to find the answer:

First of all we need to find out the molecular mass of H2SO4

• H = 1.008
• S = 32.065
• O = 16

So mass of H2 SO4 will be : (2x1.008) + (1x32.065) + (16x4)

                                          = 98.081 g/mole  

This shows that 1 mole of H2So4 contain 98 grams.

Now we need to fin out the no. of moles of H2SO4 in 250 grams

                                    250 g x (1mole/250g)

                                           = 2.5489 moles

Now we need to find out how many moles of oxygen are present in 2.5489 moles of H2SO4.

So, as mentioned in the formula of H2SO4, we can see that four moles of oxygen are present in one mole of H2SO4

It means that 2.5489 moles of H2SO4 contain:

                                      2.5489 x4

                       = 10.19565 moles of oxygen  

Now, it is very simple to determine the mass of 10.19565 moles of oxygen by using the formula:

                                no. of mole= mass/molar mass

                                     10.19565 moles= X/ 16 g

                                            10.19565 x 16= X

                                              X= 163.13 grams  

Therefore,  mass of oxygen in 250 g of H2SO4 is 163.13 grams  

Hope it help!

Answer:

thermal energy, mechanical energy  and chemical energy.

Explanation:

Our body goes into catabolism during running. Complex stored food molecules are broken down into simpler molecules that enter the blood stream and provide energy or fuel for running.  

Mechanical energy is the sum of the kinetic and potential. During running we move our limbs, set our body in motion and cover a certain distance.  Thus we utilize mechanical energy.

Thermal energy is characterized by a change in temperature. When running there is an increasing in body temperature which is manifested as sweat from the body.

thermal, mechanical, and chemical.

Answer: True

Explanation: Every atom of the same element has the same atomic number of number of protons in its core. This is why chemists say that an atom is defined by its atomic number of the number of protons.

Unlike neutrons and electrons, you can't change protons. You can change the number of neutrons and it will still be the same element, but one is going to be a little bit heavier or a little bit lighter than another.

In addition, you can change electrons which creates

ions or charged atoms.

However, you can't change the protons.

For example, hydrogen has 1 proton in its nucleus no matter what and helium has 2 protons in its nucleus no matter what and so on.

Final answer:

The statement is true. Every atom of the same element has the same atomic number, which is the number of protons in an atom's nucleus. This is a unique value defining an element.

Explanation:

The statement 'Every atom of the same element has the same atomic number' is True. The atomic number of an element is unique to that element and determines its position on the Periodic Table. It represents the number of protons in an atom's nucleus and is the fundamental property that defines an element. All atoms of the same element will have the same number of protons, and therefore the same atomic number.

Learn more about Atomic Number here:

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