This problem is honestly, very easy. Just grab a periodic table and find the element in Group 1 and Period 7. But first, let's discuss how the elements are arranged systematically in a periodic table. There are a lot of scientists who contributed to it, but the most famous one is Dimitri Mendeleev. He arranged the elements according to their atomic number. The elements starts from 1 which is Hydrogen up to the heaviest known elements which is Oganesson with an atomic number of 118. As you can observe, there is a gap between groups 3 and 4. This is done so that the periodic table does not take too much space horizontally. Thus, they are just placed at the bottom. These elements are called lanthanides (upper row) and actinides (lower row). The rows in the periodic table are called groups, and the columns are called periods.
Now, the element at the lower left corner (Group 1, Period 7) is Francium, abbreviated as Fr. It has an atomic number of 87. Some elements are actually synthesized, but Francium is a naturally occurring radioactive element. It was discovered by Marguerite Perey in France.
Answer:
there are 0.074 moles in 2.3 grams of phosphorus
Nitrogen gas could not be an input
<h3>
Answer:</h3>
1.37 × 10²³ formula units MgCl₂
<h3>
General Formulas and Concepts:</h3>
<u>Math</u>
<u>Pre-Algebra</u>
Order of Operations: BPEMDAS
- Brackets
- Parenthesis
- Exponents
- Multiplication
- Division
- Addition
- Subtraction
<u>Chemistry</u>
<u>Atomic Structure</u>
- Reading a Periodic Table
- Avogadro's Number - 6.022 × 10²³ atoms, molecules, formula units, etc.
<u>Stoichiometry</u>
- Using Dimensional Analysis
<h3>
Explanation:</h3>
<u>Step 1: Define</u>
[Given] 21.6 g MgCl₂
<u>Step 2: Identify Conversions</u>
Avogadro's Number
[PT] Molar Mass of Mg - 24.31 g/mol
[PT] Molar Mass of Cl - 35.45 g/mol
Molar Mass of MgCl₂ - 24.31 + 2(35.45) = 95.21 g/mol
<u>Step 3: Convert</u>
- [DA] Set up:
- [DA] Multiply/Divide [Cancel out units]:
<u>Step 4: Check</u>
<em>Follow sig fig rules and round. We are given 3 sig figs.</em>
1.36619 × 10²³ formula units MgCl₂ ≈ 1.37 × 10²³ formula units MgCl₂
Answer: 2
Explanation: Greenhouse gases are very important in keeping our planet just right. If we have too many Greenhouse gases it would be too hot, but we can't eliminate all of them or it will be too cold