Answer:
D. They have the same number of valence electrons
Explanation:
- The periodic table arranges elements into rows known as periods and columns known as groups or families.
- Elements in the same group share similar chemical properties.
- Additionally, they have the same number of valence electrons. For example, elements in group I have one valence electrons while those in group II have two valence electrons.
- Elements in the same period share similar features such as having the same number of energy levels. For example elements in period 4 have four energy levels.
Answer:Step 1: Gather the Needed Materials (coffee Filter, Pencil, Beaker, Water Soluble Pen/marker, Water) Step 2: Cut a Strip of Filter Paper From the Coffee Filter and Using the Marker Draw a Thick Line Near the Bottom of the Filter Paper- About 1/4 Inch From the Bottom. Step 3: Allow the Water to Move Up the Paper for Approx. 5 Minutes and Then Remove the Strip From the Water Step 4: Students Should Identify the Individual Colors in the Chromatogram That Make Up the Markers Unique Mix of Ink. Step 5: Once Students Have Mastered the Technique Its Time to Put Their Skills to the Test in "The Case of the Celebrity Dog-napping" Step 7: Write the Ransom Note on a Piece of Filter Paper in One of the Suspect Inks.
Explanation: Chromatography is the physical separation of a mixture into its individual components. This lesson integrates mixtures, solutions & solubility into an activity where students will identify the solute & the solvent. Because chromatography can be used to separate the components of inks & dyes, students are able to identify the unique "recipe" that makes up the mixture of a specific brand of pen. After the students are taught the ink chromatography technique, the fun can continue with a mini forensic investigation, "The Case of the Celebrity Dog-napping".
hopes this helps
Answer:
0.670 mol
Explanation:
Step 1: Write the balanced reaction for the decomposition of alumina
2 Al₂O₃ ⇒ 4 Al + 3 O₂
Step 2: Calculate the moles corresponding to 34.2 g of Al₂O₃
The molar mass of Al₂O₃ is 101.96 g/mol.
34.2 g × 1 mol/101.96 g = 0.335 mol
Step 3: Calculate the moles of Al produced from 0.335 moles of Al₂O₃
The molar ratio of Al₂O₃ to Al is 2:4.
0.335 mol Al₂O₃ × (4 mol Al/2 mol Al₂O₃) = 0.670 mol Al
Answer:
45.77 × 10²³ atoms
Explanation:
Given data:
Number of moles of iron = 7.6 mol
Number of atoms = ?
Solution:
Avogadro number:
The given problem will solve by using Avogadro number.
It is the number of atoms , ions and molecules in one gram atom of element, one gram molecules of compound and one gram ions of a substance. The number 6.022 × 10²³ is called Avogadro number.
1 mole = 6.022 × 10²³ atoms
7.6 mol × 6.022 × 10²³ atoms / 1 mol
45.77 × 10²³ atoms
It would be classified as decomposition reaction
