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alisha [4.7K]
3 years ago
6

What percentage of radioactive substance remains after two half-lives

Chemistry
1 answer:
Ksju [112]3 years ago
3 0

Answer:

After 2 half-lives there will be 25% of the original isotope, and 75% of the decay product. After 3 half-lives there will be 12.5% of the original isotope, and 87.5% of the decay product. After 4 half-lives there will be 6.25% of the original isotope, and 93.75% of the decay product.

Explanation:

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Hot coffee in a mug cools over time and mug warms up. Which describes the energy In this system
GenaCL600 [577]

Answer:

The average kinetic energy of the particles in the mug decreases. The average kinetic energy of the particles in the coffee increases. Thermal energy from the mug is transferred to the coffee. Thermal energy from the coffee is transferred to the mug.

8 0
3 years ago
Read 2 more answers
A spectator ion is (Select all that apply.) a. an ionic component of a reactant that is unchanged by the reaction your eye, b. c
DENIUS [597]

Correct Question:

A spectator ion is (Select all that apply.)

- a piece of french fry contaminating the reaction mixture

- an ionic component of a reactant that is unchanged by the reaction

-in this experiment, nitrate ion

- your eye, carefully watching the progress of the reaction

Answer:

- an ionic component of a reactant that is unchanged by the reaction

Explanation:

A spectator ion is an ion that exists as a reactant and a product in a chemical equation. A spectator ion is one that exists in the same form on both the reactant and product sides of a chemical reaction.

Spectator ions are ions that are present in a solution but don't take part in the reaction. When reactants dissociate into ions, some of the ions may combine to form a new compound. The other ions don't take part in this chemical reaction and are therefore called spectator ions.

The correct option is therefore the option;

- an ionic component of a reactant that is unchanged by the reaction

5 0
3 years ago
Help please and thanks
Likurg_2 [28]
The first one is 2
The second is 1
The third is 6
And the fourth is 3
4 0
4 years ago
Based on solubility rules what ions in water might interfere with the analysis of calcium ions by precipitation of calcium carbo
Pavlova-9 [17]
First, we must know what happens in the precipitation reaction. This type of reaction is a double replacement reactions. It is consists of two reactant compounds which interchange cations and anions to form two products. One of the products is an insoluble solid called a precipitate. For the precipitation of CaCO₃, there are two consecutive reactions involved:

1. Slaking of quicklime, CaO
    CaO + H₂O ⇒ Ca(OH)₂

2. Precipitation
    Ca(OH)₂ + CO₂ ⇒ CaCO₃ + H₂O

The ions that make up the H₂O molecule are H⁺ and OH⁻. According to solubility rules, the cation (positively charged ion) is likely to be attracted to an anion (negatively charged ion). Together, they form an ionic bond. This type of bond is when there is a complete transfer of electrons between the two. The Ca²⁺ cation lacks 2 electrons, while the anion OH⁻ has an excess 1 electron. In order to be stable, 1 Ca²⁺ ion and 2 OH⁻ ions must combine.

Therefore, the answer is OH⁻ ion.
6 0
3 years ago
Read 2 more answers
This <br> Question please
Marizza181 [45]

Answer:

See detailed explanation.

Explanation:

Hello!

i. In this case, since the given chemical reaction is exothermic due to the negative change in the enthalpy of reaction, we infer that according to the mentioned principle, by lowering the temperature the reaction will shift rightwards and therefore the yield is increased; thus, you need a lower temperature than the specified.

ii. In this case, since the reaction has less moles at the products side, according to the mentioned principle it'd be necessary to rise the pressure in order to increase the yield, since the increase of pressure favors the reaction side with the fewest number of moles.

Best regards!

4 0
3 years ago
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