Which statement is true of a rock layer that had another rock layer deposited on top of it?

Why isn't the mass of the electron included in the mass of an atom on the periodic table?

marta [7]

Its A because............

5 0

4 years ago

Which of the following represents the ground state electron configuration for the Mn3 ion?

Allisa [31]

Answer:

$1s^2 2s^2 2p^6 3s^2 3p^6 4s^2 3d^2$

Explanation:

The $Mn^{+3}$ has 22 electrons arround the nucleous. Its ground state configuration following the diagonal rule is:

$1s^2 2s^2 2p^6 3s^2 3p^6 4s^2 3d^2$

In term of the previous noble gas:

$[Ar] 4s^2 3d^2$

7 0

3 years ago

For each of the following, indicate if the number of half-lives elapsed is:

Hunter-Best [27]

Answer:

a. one half-life

b. three half-lives

c. two half-lives

Explanation:

The number of half-lives elapsed, n, is calculated dividing the time by the half-life time:

n = time / half-life time

a. A sample of Ce-141 with a half-life of 32.5 days after 32.5 days

n = 32.5 days / 32.5 days = 1 half-life

b. A sample of F-18 with a half-life of 110 min after 330 min

n = 330 min / 110 min = 3 half-lives

c. A sample of Au-198 with a half-life of 2.7 days after 5.4 days

n = 5.4 days / 2.7 days = 2 half-lives

4 0

3 years ago

Which of the following is most likely to make scientific knowledge stronger?

Mariulka [41]

Answer:

D) Evaluating it with experimentation and argument.

Explanation:

If you don't have enough observational evidence, then you can't really strengthen your scientific knowledge, because you haven't collected enough information to answer the questions you're asking.

If you only have a few scientists working on a question, it will take longer to find an answer. With more people working on a concept, it can be solved in more time.

It can be good to create new hypotheses, but only if you've already tested your original hypothesis (with experimentation and argument), and it turned out to be wrong. Once you've rejected your first hypothesis, only then should you make a new one.

8 0

3 years ago

BrO3- (aq) + NO2(aq) → Br-(aq) + NO3-(aq) Balance this reaction in acidic conditions?

Thepotemich [5.8K]

Answer:

BrO₃⁻ (aq) + NO₂(aq) + 4 H⁺→ Br⁻(aq) + NO₃⁻ + 2 H₂O

Explanation:

The law of conservation of matter states that since no atom can be created or destroyed in a chemical reaction, the number of atoms that are present in the reagents has to be equal to the number of atoms present in the products.

Then, you must balance the chemical equation. For that, you must first look at the subscripts next to each atom to find the number of atoms in the equation. If the same atom appears in more than one molecule, you must add its amounts.

The coefficients located in front of each molecule indicate the amount of each molecule for the reaction. This coefficient can be modified to balance the equation, just as you should never alter the subscripts.

By multiplying the coefficient mentioned by the subscript, you get the amount of each element present in the reaction.

Then, taking into account all of the above, you can determine the amount of elements on each side of the equation:

Left side: 1 Br, 5 O and 1 N

Right side: 1 Br, 3 O and 1 N

If the reaction occurs in an acidic medium:

Each excess oxygen atom is balanced by adding a molecule of water to the other side of the reaction.
Hydrogens are balanced by adding protons (H⁺) on the opposite side to the water molecules.

So, balancing the oxygen:

BrO₃⁻ (aq) + NO₂(aq) → Br⁻(aq) + NO₃⁻ + 2 H₂O

Left side: 1 Br, 5 O and 1 N

Right side: 1 Br, 5 O, 1 N and 4 H

Then, balancing the hydrogens:

BrO₃⁻ (aq) + NO₂(aq) + 4 H⁺→ Br⁻(aq) + NO₃⁻ + 2 H₂O

Left side: 1 Br, 5 O, 1 N and 4 H

Right side: 1 Br, 5 O, 1 N and 4 H

You can see that you have the same amount on each side of the reaction. So the reaction is balanced.

6 0

3 years ago

Which statement is true of a rock layer that had another rock layer deposited on top of it?​

Which statement is true of a rock layer that had another rock layer deposited on top of it?