On a hot summer day Lam walked home from his grandmothers with a chocolate bar in his pocket. When he arrived home the chocolate bar had melted in his pocket, which statement BEST explains why thechocolate bar melted?
A Heat transferred from the chocolate bar to his pocket.
B. Heat evaporated from his pocket to his chocolate bar.
c. Heat condensed from his leg to his chocolate bar in his pocket.
D. Heat transferred from the environment to the chocolate bar in his pocket.

Answer:

The amount of energy release a reaction is depended on how strong the binding energy hold the particles together

In nuclear reaction, they're breaking nucleus bind apart , which create a huge amount energy that cause by the separation of the bind. The amount is far greater than in chemical reaction which only separate the binds of electrons.

Explanation:

The half life of sodium -24 is 15 hour.

What is half life?

The duration needed for an amount to decrease to half its original is known as the half-life.

What is sodium-24?

Sodium is a kind of element which has atomic number 11. It has three isotopes.

The radioactive isotope sodium-24, which is employed in blood tests in medicine, degrades through beta decay as well as seems to have an of 15.0 hours.

Therefore, the half life of sodium -24 is 15 hour.

To know more about half life.

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Answer:the correct options are A (H⁺(aq)) and E (Mg₃(PO₄)₂(s)).

Explanation:To determine which substances are present in the net ionic equation for the reaction between MgCl2(aq) and H3PO4(aq), we first need to write the balanced molecular equation and then separate it into ions to identify the spectator ions. Spectator ions are those ions that do not participate in the chemical reaction and remain unchanged.

First, let's write the balanced molecular equation:

MgCl2(aq) + 2H3PO4(aq) -> Mg3(PO4)2(s) + 6HCl(aq)

Now, let's break down the equation into ions:

Mg²⁺(aq) + 2Cl⁻(aq) + 2H₃PO₄(aq) -> Mg₃(PO₄)₂(s) + 6H⁺(aq) + 6Cl⁻(aq)

Now, let's identify the spectator ions, which are the ions that appear on both sides of the equation and do not change:

- Mg²⁺(aq) is present on both sides.

- Cl⁻(aq) is present on both sides.

So, the spectator ions are Mg²⁺(aq) and Cl⁻(aq).

Now, let's determine the substances that are part of the net ionic equation, excluding the spectator ions:

Net Ionic Equation: 2H₃PO₄(aq) -> Mg₃(PO₄)₂(s) + 6H⁺(aq)

From the net ionic equation, the following substances are present:

A. H⁺(aq)

E. Mg₃(PO₄)₂(s)

So, the correct options are A (H⁺(aq)) and E (Mg₃(PO₄)₂(s)).

The other ions and compounds do not participate directly in the net ionic reaction and are spectator ions.

Answer: 484.94 K

Explanation:

T2 = T1 X V2 / V1

Temperature must be in kelvin so 543 + 273.15 =816.15

816.15 X 51.1 / 86

Answer: We can use the combined gas law to solve this problem:

(P₁V₁/T₁) = (P₂V₂/T₂)

where P is pressure, V is volume, and T is temperature in Kelvin.

We know that P₁ = P₂ (the pressure is assumed to be constant), and we are given V₁, T₁, and V₂. We can solve for T₂:

(P₁V₁/T₁) = (P₂V₂/T₂)

T₂ = (P₂V₂/T₁) * (T₁/P₁V₁)

We need to convert the initial temperature from Celsius to Kelvin:

T₁ = 543 + 273 = 816 K

Substituting the values:

T₂ = (1 atm * 86 mL / 816 K) * (51.1 mL / 1 atm * 86 mL)

T₂ = 0.0629 * 51.1 * 1000 = 3217 K

Therefore, the marshmallow would need to be heated to a temperature of 3217 K for its volume to change from 86 mL to 51.1 mL.

Enjoy (:

Answer:

yes

Explanation:

that is the answer