put the glass lid on and turn or turn down the heat
which of these elements has two valence electrons?
a. hydrogen (H)
b. barium (Ba)
c. nitrogen (N)
d. krypton (Kr)
e. bromine (Br)
*CAN SOMEONE HELP ME PLEASE*
Answer:
d
Explanation:
the answer is d is that correct
A compound being used in experimental medicine is 78.14% boron (B) and 21.86% hydrogen (H). The empirical formula of the compound will have a boron to hydrogen ratio of
Explanation:
I did it step by step so It would be easier to understand:)
An inverse relationship can be represented by what?
Answer:
1/....
Explanation:
If we say acceleration 'a' is inversely proportional to mass 'm', then
a=1/m.
hyy guys.... can you plz writ me a journal plz ..... connection with science... any topic will be done today is my submition
ur best try is to copy and paste and change some words.
A population of Esherichia coli is given time to grow for eight generations. The final population is 1,996,800 cells. What was the initial population in cells?
Answer:
7800 cells
Explanation:
The number of Escherichia coli cells N after n generations is given by
N = 2ⁿ × N₀ where N₀ = initial population
Now making N₀ subject of the formula, we have
N₀ = N/2ⁿ
Since n = 8 and N = 1,996,800 cells, substituting the values of the variables into the equation, we have
N₀ = N/2ⁿ
N₀ = 1,996,800 cells/2⁸
N₀ = 1,996,800 cells/256
N₀ = 7800 cells
So, the initial population of Escherichia coli cells is 7800 cells.
La formula quimica de la molecula de agua H20 , si H = 1 gramos y O = 16 gramos . Cual es su composicion porcentual ? 88,88 % de O y 11,11 % de H 88,88 % de H Y 11,11% de O 80 % de O Y 20 % de H 90% de O Y 10 % de H
Answer:
88,88 % de O y 11,11 % de H
Explanation:
La composición porcentual se define como la masa que hay de cada mol de átomo en 100g. Las moles de agua en 100g son:
Masa molar agua:
2H = 2*1g/mol = 2g/mol
1O = 1*16g/mol = 16g/mol
Masa molar = 2 + 16 = 18g/mol
100g H2O * (1mol / 18g) = 5.556 moles H2O.
Moles de hidrógeno:
5.556 moles H2O * (2mol H / 1mol H2O) = 11.11 moles H
Moles Oxígeno = Moles H2O = 5.556 moles
La masa de hidrógeno es:
11.11mol * (1g/mol) 11.11g H
La masa de oxígeno es:
5.556 mol * (16g / 1mol) = 88.89g O
Así, el porcentaje de O es 88.89% y el de H es 11.11%. La opción correcta es:
88,88 % de O y 11,11 % de HDescribe the chemical reaction based on the chemical equation below. Also, explain whether the equation is balanced. NH3(g)+o2=NO(g)+H2O(I)
Answer:
2 moles of ammonia gas (NH₃) reacts with 5/2 moles of oxygen gas (O₂) to produce 2 moles of nitrogen monoxide gas (NO) and 3 moles of liquid water (H₂O)
Explanation:
The chemical equation is:
NH₃(g) + O₂(g)⇒ NO(g) + H₂O(I)
First, we have to distinguish which are reactants and which are products.
Reactants ⇒ left side: NH₃ (ammonia gas) and O₂ (oxygen gas)
Products ⇒ right side: NO (nitrogen monoxide) and H₂O (water)
Thus, ammonia gas reacts with oxygen gas to produce nitrogen monoxide gas and liquid water.
The reaction is not balanced, because it does not has the same number of atoms of each chemical element in both sides. To balance, we have to write a coefficient of 3 for H₂O, then a coefficient of 2 for NH₃ (to balance H atoms), then a coefficient of 2 for NO, and finally a coefficient of 5/2 for O₂ (to obtain 5 atoms of O in both sides):
2 NH₃(g) + 5/2 O₂(g)⇒ 2 NO(g) + 3 H₂O(I)
According to the balanced equation, 2 moles of ammonia gas (NH₃) reacts with 5/2 moles of oxygen gas (O₂) to produce 2 moles of nitrogen monoxide gas (NO) and 3 moles of liquid water (H₂O).
What happens to the hydrogen ion (H+) concentration as an aqueous
solution becomes more acidic? *
A)decreases
B)increases
C)remains constant
D)cannot be determined
Answer:
Explanation:
It can be determined by measuring the Ph. D is incorrect.
C: is wrong because if you are making something acidic, you are increasing the H+
B: is the correct answer.
A: pH decreases. H+ increases which makes the Ph decrease. It is an oddity of the formula that makes this happen.
The titration should be stopped when the solution in the flask changes color and the new color remains even when the solution is gently shaken. True False
The above given statement is true.
What is solution?A homogeneous mixture comprised of two or more components is referred to as a solution. Because they are consistently scattered at the molecular or ionic level, the components in a solution are evenly mixed and have a constant composition.
Until the reaction between the two solutions is complete, a solution of known concentration is gradually added to a solution of unknown concentration in a titration. The endpoint, or point at which the reaction is finished, is often identified by a color change that takes place after an indicator is added to the solution being titrated.
The reaction has achieved its endpoint when the solution in the flask changes color, and the new color persists even after the solution is gently shaken. At this time, the titration should be halted. By doing this, it is possible to precisely determine the concentration of the unknown solution and the volume of titrant added to the solution.
To know more about solution, visit:
https://brainly.com/question/30665317
#SPJ1
how many moles are in 20 grams of argon
Answer:
There are 0.5 mole in 20g of argon.
Explanation:
40 g of argon = 1mole
Then 20g of argon is,
→ 1/40 × 20
→ 0.5 mole
Answer:
[tex]n = \frac{mass}{molar \: mass} \\ n = \frac{20g}{39.948 \frac{g}{mol} } \\ n = 0.5 \: mol \: of \: argon[/tex]
Explanation:
hope this makes sense
:)
How much pressure should an airbag have?
Answer:
It should have about 70-80 pounds of air pressure.
Answer:
5 lbs is what I read on the internetluv </3
Which property of metals makes them good conductors of electricity?
A. Their melting point
B. Their mobile electrons
C. Their hardness
D. Their ductility
Answer:
their mobile electrons
write the name and the formula of the compound formed Potassium and oxygen, and Aluminum and nitrogen.
Answer:
K2O Potassium oxide
Explanation:
6. You have a sample of H2Ois, with a mass 23.0 grams at a temperature of 46.0
temperature water would be in what state? Use reference table on page 492 for specific heat
capacity of ice). How many kilojoules of heat energy are necessary to carry out each step? Also
calculate the total amount of energy needed.
a) heat the ice to 0.0 °C?
Answer: I think it would be -23
Explanation:
Which process, in order, would be necessary for this sequence of the rock cycle:
rock → metamorphic rock → igneous rock
Heat and pressure → melting → cooling
Weathering and erosion → compaction → weathering and erosion
Melting → cooling → melting → erosion
Cooling → melting → cooling → weathering and erosion
Answer:
may be the answer is Heat and pressure - melting - cooling
Please somone help me with a chemistry question brainliest to whoever answers correctly and 20 points
Answer:
342.15 g/mol
..........
The molar mass of copper(II) chloride (CuCl2) is 134.45 g/mol. How many formula units of CuCl2 are present in 17.6 g of CuCl2?
Answer:
7
Explanation:
took test
a reaction of heating patassium permanganate produces potassium manganate, manganese dioxide and oxygen gas. Heat 15.8 g potassium permanganate until no more oxygen gas is given off. The remaining material has a mass of 14.2 g. What mass of oxygen gas was produced in the reaction?
La columna de la izquierda corresponde a los tipos de sales y la columna derecha a los tipos de fórmula que presentan. Relacionar con el mismo COLOR las parejas correspondientes. 1. Hidracidas a. MX 2 Acidas b. MXO 3. Oxacidas c. MHXO 4. Basicas d. M(OH)XO
Answer:
1. Hidracidas a. MX
2 Acidas c. MHXO
3. Oxacidas b. MXO
4. Basicas d. M(OH)X
Explanation:
¡Hola!
En este caso, de acuerdo con el concepto de sal, la cual está generalmente dada por la presencia de al menos un metal y un no metal, es posible encontrar cuatro tipos de estas; hidrácidas, oxácidas, básicas y ácidas, en las que las primeras dos son neutras pero la segunda tiene presencia de oxígeno, la tercera tiene iones hidróxido adicionales y la cuarta iones hidrógeno de más.
Debido a la anterior, es posible relacionar cada pareja de la siguiente manera:
1. Hidracidas a. MX
2 Acidas c. MHXO
3. Oxacidas b. MXO
4. Basicas d. M(OH)XO
En las que M se refiere a un metal, X a un no metal, H a hidrógeno y O a oxígeno.
¡Saludos!
1. How many molecules of S2 gas are in 756.2 L?
a. 2.032 x 1025 molecules S,
b. 3.022 x 1023 molecules S,
c. 4.302 x 10 molecules S
d. 8.203 x 10' molecules S2
Answer: There are [tex]2.032 \times 10^{25}[/tex] molecules [tex]S_{2}[/tex] gas are in 756.2 L.
Explanation:
It is known that 1 mole of any gas equals 22.4 L at STP. Hence, number of moles present in 756.2 L are calculated as follows.
[tex]Mole = \frac{Volume}{22.4 L}\\= \frac{756.2 L}{22.4 L}\\= 33.76 mol[/tex]
According to mole concept, 1 mole of every substance contains [tex]6.022 \times 10^{23}[/tex] molecules.
Therefore, molecules of S present in 33.76 moles are calculated as follows.
[tex]1 mol = 6.022 \times 10^{23}\\33.76 mol = 33.76 \times 6.022 \times 10^{23}\\= 2.032 \times 10^{25}[/tex]
Thus, we can conclude that there are [tex]2.032 \times 10^{25}[/tex] molecules [tex]S_{2}[/tex] gas are in 756.2 L.
What is the mass percentage of copper in a 250 g sample of brass. Brass is made of copper and zinc and copper content of the sample is 150 g
Answer:
Percentage of copper in sample = 60%
Explanation:
Given:
Mass of copper = 150 gram
Mass of brass = 250 gram
Find:
Percentage of copper in sample
Computation:
Percentage of copper in sample = [Mass of copper / Mass of brass]100
Percentage of copper in sample = [150/250]100
Percentage of copper in sample = [0.6]100
Percentage of copper in sample = 60%
Considering the temperature vs. time graph below, how does the temperature at the beginning of a change of state
compare with the temperature at the end of the change?
Answer:
The temperature on the graph is higher at point 5 than at point 1. The correct answer is the last answer choice that you showed.
Explanation:
The temperature at point 1 is -10 degrees Celsius, while the temperature at point 5 is 120 degrees Celsius. This is a 1300% increase.
See the calculation here: https://www.calculatorsoup.com/calculators/algebra/percent-change-calculator.php?v_1=-10&v_2=120&action=solve
I hope this helps.
Is proton number always equal to electron number ?
Explanation:
this is ur answer i hope.........
What factors generally determine whether a reaction happens or not?
A. Reaction rate and color
B. Presence of water and salt
C. Enthalpy and entropy
D. Keg and Ka
Answer:
Explanation:
The answer is C Enthaply and entropy because temperature plays a big role in reactions
Answer:
c
Explanation:
a p e x :)
Pure hydrogen (H₂) is a hazardous substance. Thus, safer and more cost effective techniques have been developed to store it as a solid for shipping purposes. One such method is the reaction below, which occurs at 200 °C.
Answer: hello your question has some missing details attached below is the missing details
answer : 25.5% ( B )
Explanation:
Determine percentage yield
molar mass = 35 g/mol
mass of Li₃N(s) = 70 g
product LiH(s) = 8.0 g ( actual yield )
theoretical yield ( LiH ) = 4 * 7.95 = 31.8 g
percentage yield = actual yield * 100 / theoretical yield
= 8 * 100/31.8
= 25.5%
What is the mass of 0.251 moles of water? Using dimensional analysis show work
[tex]1 \text{ mol of H}_2 \text{O} \equiv 18 \text{ g} \implies 0.251 \text{ moles of H}_2 \text{O} \equiv 4.518 \text{ g}[/tex]
Hey everyone, I'm starting honors chemistry next year and I want to get prepared for the class. What are the basic keys information that I need to know for the subject.
Thanks!
Answer:
hi!
Explanation:
Well, some things I would do is to know the Periodic Table font and back. Know they elements and their class and atomic number and weight. Know how many atoms make up each element and how many protons, neutrons, and elements are in each atom.
How many grams of calcium chloride would you measure if you needed to
add 0.125 moles of calcium chloride to 100mL of water?
Answer: cuhh
Explanation:
¡A que clasificación corresponden las sustancias que están formadas por un mismo tipo de átomos, es homogénea y no puede descomponerse por medios químicos?
Answer:
Elementos.
Explicación:
Los elementos son las sustancias puras que están formadas por el mismo tipo de átomos, es homogéneo y no se puede descomponer por medios químicos. El elemento tiene el mismo tipo de átomos que son similares en tamaño y forma. Es un tipo de materia pura que tiene solo un tipo de átomos y no se puede descomponer más porque no está hecha de dos sustancias, es solo una sustancia, por eso no se puede descomponer por medios químicos.