Calculate the mass of iron oxide that contains a trillion iron atoms

Provide at least three indicators of a chemical change that are present in burning a piece of paper.

Pie

Answer:

Some chemical indicators perceived while a piece of paper is burning are:

Production of an Odor: there is a smell of burnt paper

Change in Temperature: combustion is a highly exothermic reaction , so the temperature increase

Change in Color: paper changes to ashes as the burning process occurs

3 0

3 years ago

What type of Radioactive decay is occurring in the following reaction?

Blababa [14]

Radioactive decay is the loss of energy by unstable atomic nuclei. The reaction shows alpha decay. Thus, option d is correct.

<h3>What is alpha decay?</h3>

Alpha decay is a type of radioactive decay in which an alpha particle or the helium ion is released from the parent cell to produce the daughter nucleus.

The alpha decay in the isotope of the uranium to thorium and an alpha particle is shown as:

²³⁵U₉₂ → ²³¹Th₉₀ + ⁴He₂

In beta decay, a negatively charged electron is emitted along with the daughter nucleus and in gamma decay, gamma rays without charge and mass are emitted.

Therefore, the reaction shows option d. alpha decay.

Learn more about alpha decay here:

brainly.com/question/25013071

#SPJ1

3 0

2 years ago

The freezing point of water H2O is 0.00°C at 1 atmosphere. A nonvolatile, nonelectrolyte that dissolves in water is urea. If 13.

Trava [24]

Answer:

Molality = 1.46 molal

The freezing point of the solution = -2.72 °C

Explanation:

Step 1: Data given

The freezing point of water H2O is 0.00°C at 1 atmosphere

urea = nonelectrolyte = van't Hoff factor = 1

Mass urea = 13.40 grams

Molar mass urea = 60.1 g/mol

Mass of water = 153.2 grams

Molar mass H2O = 18.02 g/mol

Kf = 1.86 °C/m

Step 2: Calculate moles urea

Moles urea = mass urea /molar mass urea

Moles urea = 13.40 grams / 60.1 g/mol

Moles urea = 0.223 moles

Step 3: Calculate the molality

Molality = moles urea / mass water

Molality = 0.223 moles / 0.1532 kg

Molality = 1.46 molal

Step 4: Calculate the freezing point of the solution

ΔT = i * Kf * m

ΔT = 1* 1.86 °C/m * 1.46 m

ΔT = 2.72 °C

The freezing point = -2.72 °C

3 0

3 years ago

This is really hard help pls

deff fn [24]

The answers are A. Pseudoscience is often based only on opinions; D. Pseudoscience often involves explanations of beliefs; E. Pseudoscience includes subjective ideas.

Explanation:

Pseudosciences comprises disciplines or theories that do not follow scientific standards but claim to be factual. This includes areas such as clairvoyance or astrology because this is not based on evidence but subjectivity. Indeed, the base of most pseudosciences are personal beliefs, opinions, or subjective ideas. Moreover, complex theories or methods are created to try to explain these beliefs, but because they do not follow scientific standards they are not considered as valid. In this context, options A, D, and E are correct.

4 0

4 years ago

Fe2O3 + Al ---> Fe + Al2O3

PIT_PIT [208]

Answer:

$Fe2O3 + 2Al \rightarrow 2Fe + Al2O3$

Explanation:

Hello!

In this case, when balancing chemical reactions, we must make sure that the atoms of each element are the same at both reactants and products; thus, for the given reaction, we need two iron and aluminum atoms at each side based on their subscripts in the given oxides as shown below:

$Fe2O3 + 2Al \rightarrow 2Fe + Al2O3$

Best regards!

5 0

3 years ago