CHEMISTRY HIGH SCHOOL

Which pure substance can be classified as an element?
-H2
-NO3
-NaCl
-H2SO4

Answers

Answer 1
Answer: An element is made up of only one kind of atom.
So H2 is the element. Why? because H2 is made up of only one kind of atom, hydrogen atoms.

- Just as a side note, compounds (made up of atoms from more than one element) are also considered pure substances.
Answer 2
Answer:

Answer: H2

Explanation: i took the quizz

Related Questions

Science Experiments: What does Interpretation of Data mean?
Solutions are a mixture of 2 or more compounds true or false
A student balanced the chemical equation Mg + O2 →MgO by writing Mg + O2 → MgO2. Was the equation balanced correctly? Explain your answer. If the equation was not balanced correctly, write the correctly balanced equation.
Giving brainliest if correct!! please help someone out?
What is true of an Arrhenius acid?a. An Arrhenius acid donates OH- ions.b. An Arrhenius acid donates H+ ions.c. An Arrhenius acid accepts H+ ions.d. An Arrhenius acid accepts OH- ions.

Which of the following pH values indicates the highest concentration of hydronium ions in a solution?

Answers

pH value is the power of the hydrogen ions concentration in a solution. The more is the concertation more basic will be the solution, Less is the concertation more will be an acidic solution.

  • The highest concertation of ions is 1.0 as the lower is pH level the higher is the concentration of ions. Hence the option B 1.0 has an aqueous solution that has more ions.

Learn more about the pH values indicating the highest concentration.

brainly.com/question/20161888.
Hydronium ions are H30+, and pH = -log10[H+] 

As H+ ions in solution exist as H3O+ ions, the lower the pH, the higher the concentration of H30+

Which of the following atoms releases more energy than oxygen when an electron is added to its valence energy level? Select one:
a. helium (He)
b. fluorine (F)
c. carbon (C)
d. nitrogen (N)

Answers

The answer is b. fluorine (F). This is because fluorine is a more electronegative (electron loving) atom compared to oxygen. It is found on the 7th group of the periodic table, so it has 7 valence electrons. It only needs one more electron to achieve the ideal number of valence electrons which is 8. Oxygen, on the other hand, is in group 6 so it needs 2 more electrons to complete its valency. Helium can't be the answer because it is already in group 8, meaning it is already stable and won't release energy.

when this equation is correctly balanced using smallest whole numbers, what is the coefficient of O2(g)

Answers

When the equation is correctly balanced , the coefficient of O₂ = 3.

What is Balancing of Equation ?

The amounts of reactants and products required to satisfy the Law of Conservation of Mass are given in a balanced chemical equation.

This  indicates that on the reactant side of the equation, there are the same number atom as there are on the product side of the equation.

In the question the given equation is

C₂H₄+O₂→CO₂+H₂O

When the equation is correctly balanced using smallest whole numbers

C₂H₄+3O₂→2CO₂+2H₂O

To determine if the equation is balanced or not , if we will check the reactant molecules with the product molecules.

C = 2 in reactant and product

O=6  in reactant and product

H=4 in reactant and product

So the equation is balanced

and so the coefficient of O₂ = 3

To know more about the balancing of Equation

brainly.com/question/7181548

#SPJ2
The subscript is 2, while the coefficient, since it has non, it would be a one. 

Answer: one

The cell theory teaches that _____.the basic unit of life is the organism
the basic unit of life is the cell
all cells have the same basic structure
cells are miniature reflections of the organisms from which they are taken

Answers

The cell theory teaches that :

the basic unit of life is the cell
Explanation:

In biology, a scientific theory is that the historical theory, currently universally accepted, that living organisms square measure created from cells, that they're the fundamental structural/organizational unit of all organisms, which all cells come back from pre-existing cells. Cells square measure the fundamental unit of structure all told organisms and conjointly the fundamental unit of the replica.

Answer:

the basic unit of life is the cell

If enough heat was REMOVED from B, it would change into ____________.

Answers

If enough heat was REMOVED from B, it would change into A.

An exothermic reaction is a reaction that releases energy, this energy is usually in the form of heat. An endothermic reaction is a reaction that absorbs energy to take place.

To bring molecules together requires the release of energy, that is, an exothermic reaction.

Thus, if heat were removed from B, it would turn into A, with molecules closer together, in the solid state.

Learn more about exothermic reaction in: brainly.com/question/14969584
If enough heat was removed from B(liquid) it would become a solid i think.

How to know that something is a basic oxide or acedic oxides?
plz help ​

Answers

Explanation:

General Rules. In general, the electropositive character of the oxide's central atom will determne whether the oxide will be acidic or basic. The more electropositive the central atom the more basic the oxide. The more electronegative the central atom, the more acidic the oxide.
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The internal energy of a gas decreases by 1.65 kJ when it transfers 1.87 kJ of energy in the form of heat to the surroundings.(a) Calculate the work done by the gas on the surroundings. (b) Does the volume of gas increase or decrease?
How did Democritus contribute to the atomic theory/ structure of the atom?
When a neutral atom undergoes oxidation, the atom’s oxidation state(1) decreases as it gains electrons(2) decreases as it loses electrons(3) increases as it gains electrons(4) increases as it loses electrons