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adoni [48]
3 years ago
10

The validity of scientific theories and laws depends on evidence. Which of the following statements of evidence supports a law r

ather than a theory?
Electrons orbit the nucleus of an atom within a certain radius.
DNA analysis reveals that a modern species is related to an extinct species.
Seafloor spreading occurs at a rate of three centimeters per year in the mid-Atlantic.
The amount of matter in a closed system is the same at the start of a reaction as at the end of the reaction.

Chemistry
2 answers:
Ksju [112]3 years ago
4 0

Answer:

d the amount of matter in a closed system is the same at the start of a reaction as at the end of the reaction

mr_godi [17]3 years ago
3 0

Answer:

D

Explanation:

i am doing the test rn and i found the answer in other places

You might be interested in
Draw the lewis structure of ch3nc; fill in any nonbonding electrons. Calculate the formal charge on each atom other than hydroge
jenyasd209 [6]

A visual representation of covalent bonding which represents the valence shell electrons in the molecule is said to be a Lewis structure. The lines represents the shared electron pairs and dots represents the electrons that are not involved in the bonding i.e lone pairs.

Number of valence electrons in each atom:

For Carbon, C = 4

For Hydrogen, H = 1

For Nitrogen, N = 5

The Lewis structure of CH_3NC is shown in the attached image.

The formula of calculating formula charge = FC = VE - NE- \frac{BE}{2}   -(1)

where, F.C is formal charge, V.E is number of valence electrons, N.E is number of non-bonding electrons and B.E is number of bonding electrons.

Now, calculating the formal charge:

For C on left side:

FC = 4 - 0- \frac{8}{2} = 0

For N:

FC = 5 - 0- \frac{8}{2} = +1

For C on right side:

FC = 4 - 2- \frac{6}{2} = -1

The formula charge of each atom other than hydrogen is shown in the attached image.


6 0
3 years ago
If we react 5.4g of sodium chloride with an unknown amount of fluorine gas, we produce 4.9g of sodium fluoride and 3.7g chlorine
Bumek [7]

Answer:

4.43 g

Explanation:

The reaction between sodium chloride and flourine gas is given as;

NaCl + F2 --> NaF + Cl2

From the stochiometry of the equation;

1 mol of NaCl reacts eith 1 mol of F2 to form 1 mol of NaF and Cl2

Mass of 1 mol of F2 = 38g

Mass of 1 mol of sodium flouride, NaF = 42g

This means 38g of flourine reacted with NaCl to form 42g of NaF

xg of F2 would form 4.9g of NaF

38 = 42

x = 4.9

x = 4.9 * 38 / 42

x = 4.43 g

4 0
3 years ago
Explain why the electron configuration of 2-3-1 represents an atom in an excited state?
baherus [9]

Answer:

See explanation

Explanation:

If we look at the electron configuration closely, we will discover that the element must have had a ground state electron configuration of 2,4.

This is because, the innermost shell usually holds two electrons while the outer shells hold eight electrons each. The four electrons must be accommodated in the second shell in the ground state configuration of the compound.

However, when the atom is excited, one electron from this shell may move to the third shell to give the excited state configuration 2-3-1 as shown in the question.

6 0
3 years ago
28. Which statement is INCORRECT regarding radiation?
mash [69]

Answer:

Radiation is energy. It can come from unstable atoms that undergo radioactive decay, or it can be produced by machines. Radiation travels from its source in the form of energy waves or energized particles. There are different forms of radiation and they have different properties and effects.

Related information in Spanish (Información relacionada en español)

On this page:

Ionizing and non-ionizing radiation

Electromagnetic spectrum

Types of ionizing radiation

Periodic Table

Non-Ionizing and Ionizing Radiation

There are two kinds of radiation: non-ionizing radiation and ionizing radiation.

Non-ionizing radiation has enough energy to move atoms in a molecule around or cause them to vibrate, but not enough to remove electrons from atoms. Examples of this kind of radiation are radio waves, visible light and microwaves.

Ionizing radiation has so much energy it can knock electrons out of atoms, a process known as ionization. Ionizing radiation can affect the atoms in living things, so it poses a health risk by damaging tissue and DNA in genes. Ionizing radiation comes from x-ray machines, cosmic particles from outer space and radioactive elements. Radioactive elements emit ionizing radiation as their atoms undergo radioactive decay.

Radioactive decay is the emission of energy in the form of ionizing radiationHelpionizing radiationRadiation with so much energy it can knock electrons out of atoms. Ionizing radiation can affect the atoms in living things, so it poses a health risk by damaging tissue and DNA in genes.. The ionizing radiation that is emitted can include alpha particles, beta particles and/or gamma raysHelpgamma raysA form of ionizing radiation that is made up of weightless packets of energy called photons. Gamma rays can pass completely through the human body; as they pass through, they can cause damage to tissue and DNA.. Radioactive decay occurs in unstable atoms called radionuclides.

Explanation:

8 0
3 years ago
What do nonmetals and metals seek to do when having full outermost shells?
IceJOKER [234]

Answer: C

Explanation:

5 0
3 years ago
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