What's your question? Am I missing something?
Answer:
1. Jennifer
Jennifer tried to cut corners and exclude a chunk of people from the population, making her results biased.
2. Brad
Brad was just seeing what he wanted to see, instead of facing the results of his experiment, which makes him scientifically biased. It's known as 'cherry-picking' informally.
Explanation:
Why are the rest not biased?
1. Tyler
You don't need your results and conclusion to agree with your hypothesis. A hypothesis is just your guess, it's not absolute and doesn't demonstrate bias if it doesn't agree with your conclusion.
2. Manny
He simply chose a topic he was interested in. It would be a different story if he already had a topic, but only chose information that agreed with his hypothesis, neglecting other pieces of information.
3. Ellie
This demonstrates no bias. She carried out an experiment and, according to experimental data, received the same results every time. She did not purposefully alter them to make them what she wanted to see.
This problem is asking for the percent by mass of hydrogen in hydrofluoric acid. At the end, the answer turns out to be D. 5% as shown below:
<h3>Percent compositions:</h3>
In chemistry, percent compositions are used for us to know the relative amount of a specific element in a compound. In order to do so for hydrogen, we use the following formula, which can also be applied to any other element in a given compound:
Where 
stands for the atomic mass of hydrogen and 
for the molar mass of hydrofluoric acid. In such a way, we plug in the atomic masses of hydrogen (1.01 g/mol) and fluorine (19.0 g/mol) to obtain:
Learn more about percent compositions: brainly.com/question/12247957
3.4x 10^24 is how many atoms there are.
Answer:
Increases
Explanation:
You can't add more things and it not become anything more
