Answer:
3.01
Explanation:
Speed=distance/time
=100mtrs/33.2sec
=3.01m/s
Atoms of which two elements have a combined total of 23 protons?
A.Sodium, Na, and magnesium, Mg
B.Boron, B, and carbon, C
C.Copper, Cu, and zinc, Zn
D.None of these
Answer:
A
Explanation:
Sodium has 11 electrons and Magnesium has 12 electrons. Since here you need to consider atoms, they must have equal amount of protons as electrons to be considered neutral, and so an atom.
So simply 11+12 =23
what does aqueous mean
of or containing water, typically as a solvent or medium.
"an aqueous solution of potassium permanganate"
like water; watery.
"a great hall of aqueous marble"
Question 7 (5 points)
(05.01 LC)
One mole of zinc has a mass of 65.4 grams. Approximately how many atoms of zinc are present in one mole of zinc?
Answer:
6.02 x 10²³ atoms
Explanation:
The number of moles present in 1 mole of zinc will be 6.02 x 10²³ atoms. This is because a mole of any substance contains the Avogadro's number of particles which is 6.02 x 10²³ atoms.
A mole is simple a convenient way of estimating the number particles within a substance.
So every 1 mole of a substance contains the same number atom in there.
For the give zinc, since it is 1 mole, it will contain 6.02 x 10²³ atoms
they've changed the answer, but 6.02 x 1023 is still right. the new answer is just 6 x 1023.(6.02 rounded to the nearest integer)
What does the cardiovascular system do
for the human body?
Answer: The blood circulatory system (cardiovascular system) delivers nutrients and oxygen to all cells in the body.
Explanation:
9 of 16
9.
A student drops a ball from 5 feet above the ground. After bouncing once, it only reaches
a maximum height of 4 feet above the ground.
Use energy terms to explain why the ball did not reach its original height after bouncing
once.
A. Some energy was lost
B. Some energy was transferred to the floor and air
C. Some energy disappeared when it hit the floor
D. Some energy was destroyed
A process that releases heat, such as freezing or condensation is called?
Answer:
exothermic
Explanation:
An exothermic reaction gives off heat energy. Condensation is the process by which water vapor turns into liquid water. This typically occurs when water vapor molecules come into contact with cooler molecules. This causes the water vapor molecules to lose some energy as heat which is a exothermic reaction.
When water becomes a solid, it releases heat, warming up its surroundings. This makes freezing an exothermic reaction.
What is the mass, in grams, of MgCl2 is consumed when 255g Mg(OH)2 is produced?
MgCl2 + 2 LiOH → Mg(OH)2 + 2 LiCl
416 g MgCl₂
General Formulas and Concepts:Math
Pre-Algebra
Order of Operations: BPEMDAS
Brackets Parenthesis Exponents Multiplication Division Addition Subtraction Left to RightChemistry
Atomic Structure
Reading a Periodic TableStoichiometry
Using Dimensional AnalysisExplanation:Step 1: Define
[RxN - Balanced] MgCl₂ + 2LiOH → Mg(OH)₂ + 2LiCl
[Given] 255 g Mg(OH)₂
[Solve] x g MgCl₂
Step 2: Identify Conversions
[RxN] 1 mol MgCl₂ → 1 mol Mg(OH)₂
[PT] Molar Mass of Mg - 24.31 g/mol
[PT] Molar Mass of O - 16.00 g/mol
[PT] Molar Mass of H - 1.01 g/mol
[PT] Molar Mass of Cl - 35.45 g/mol
Molar Mass of Mg(OH)₂- 24.31 + 2(16.00) + 2(1.01) = 58.33 g/mol
Molar Mass of MgCl₂ - 24.31 + 2(35.45) = 95.21 g/mol
Step 3: Stoichiometry
Set up conversion: [tex]\displaystyle 255 \ g \ Mg(OH)_2(\frac{1 \ mol \ Mg(OH)_2}{58.33 \ g \ Mg(OH)_2})(\frac{1 \ mol \ MgCl_2}{1 \ mol \ Mg(OH)_2})(\frac{95.21 \ g \ MgCl_2}{1 \ mol \ MgCl_2})[/tex]Multiply/Divide: [tex]\displaystyle 416.227 \ g \ MgCl_2[/tex]Step 4: Check
Follow sig fig rules and round. We are given 3 sig figs.
416.227 g MgCl₂ ≈ 416 g MgCl₂