During an experiment, a student observes the formation of a precipitate. Why does this indicate that a chemical reaction is likely occurring?1)A solid forms, and there is a change of color.
2)A gas forms, and there is a change of color.
3)A solid forms, and light is emitted.
4)A gas forms, and light is emitted.

Answers

Answer 1

Answer: Chemical reactions involve the breaking of bonds and forming new bonds. All chemical reactions involves forming of new substances. For this, stuation, it is evident that a chemical reaction occur because a precipitate formed. Therefore the correct answer is stated in statement 1.

Answer 2

Answer: A solid forms, and there is a change of color.

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What is the process of breaking down glycogen without the presence of oxygen?

Answers

Answer:

anaerobic glycolysis

In my knowledge, this would be called anaerobic respiration – anaerobic meaning without oxygen and the respiration process is through glycolysis, the breaking down of glucose to form (with generalisations) 2 ATP molecules and lactic acid (with probably some other bits and pieces). I thought this was a biology concept? :D

Is this a good scientific question? “Is the lifespan of snowshoe hares, which are white in the winter and brown in the summer, affected by levels of winter snowfall?” A) Yes, because the question is specific. B) No, because the question cannot be tested in a laboratory. C) Yes, because the question has already been answered. D) No, because the question does not lead to a hypothesis.

Answers

The answer is: A) Yes, because the question is specific.

The scientific method is a process for experimentation that is used to explore observations (in this example color of snowshoe hares).

Steps of the scientific method:

1) ask a question about something that is observed.

2) do background research.

3) construct a hypothesis, an attempt to answer questions with an explanation that can be tested.

4) test of hypothesis.

5) analyze collected data and draw a conclusion.

The two main variables in an experiment are the independent and dependent variable.

Dependent variable is the variable being tested and measured in a scientific experiment, in this example lifespan of snowshoe hares.

Dependent variables depend on the values of independent variables. The dependent variables represent the output or outcome whose variation is being studied.

A) Yes, because the question is specific.

What kind of particles make up compound

Answers

compounds are composed of elements

elements are composed of sub atomic particles such as electrons and proton

A compound is made of of 2 or more elements. Elements are made up of atoms. So compounds are also made up of atoms because they are made up of elements.

Please comment!

What is the pH of a solution with [H+] = 1.25 mc015-1.jpg 10–10 M?

Answers

Answer : The pH of a solution is, 9.903

Explanation : Given,

Concentration of hydrogen ion = $1.25* 10^(-10)M$

pH : It is defined as the negative logarithm of hydrogen ion concentration.

Formula used :

$pH=-\log [H^+]$

Now put the value of hydrogen ion concentration in this formula, we get the pH of a solution.

$pH=-\log (1.25* 10^(-10))$

$pH=9.903$

Therefore, the pH of a solution is, 9.903

[ H+]=10-pH
it become
[H+]=0.1

Which trends are observed as each of the elements within Group 15 on the Periodic Table is considered in order from top to bottom?(1) Their metallic properties decrease and their atomic radii decrease.
(2) Their metallic properties decrease and their atomic radii increase.
(3) Their metallic properties increase and their atomic radii decrease.
(4) Their metallic properties increase and their atomic radii increase.

Answers

Answer;

-Their metallic properties increase and their atomic radii increase

Explanation;

-Group 15 is also called the nitrogen family. It consists of the elements nitrogen, phosphorus, arsenic, antimony, moscovium and bismuth. The atomic radius of these elements increases from Nitrogen to Bismuth.

-Moving down the group, the ionic radii, and atomic radii increases. This is because of the expansion of another main energy level in each progressive element.

-Moving down a group, metallic character increases. On the other hand, the ionization enthalpy of the elements decreases due to an increase in their nuclear size.

4) their metallic properties increase and their atomic radii increase.

Gloria is writing the chemical formula for a compound using its chemical name. She has just identified the names of the elements in the compound. What tool will she use next?

Answers

Gloria is writing thechemical formula for a compound using its chemical name. She has justidentified the names of the elements in the compound. The tool that she willneed to use next is a textbook to learn the IUPAC naming of compounds or ahandbook of chemical compounds.

Answer:

the periodic table

Explanation:

verified correct

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