Answer:
28
Explanation:
electron = atomic number - charge(if the charge is positive and addition if the charge is negative)
electron = 30 - 2
electron = 28
How can you find the amount of valence electrons an atom of an element contains?
Answer:
For neutral atoms, the number of valence electrons is equal to the atom's main group number. The main group number for an element can be found from its column on the periodic table. For example, carbon is in group 4 and has 4 valence electrons. Oxygen is in group 6 and has 6 valence electrons.
Explanation:
17.Oxygen gas can be prepared by heating potassium chlorate according to the following equation:
2KClO3(s)2KCl(s) + 3O2(g)
The product gas, O2, is collected over water at a temperature of 25 °C and a pressure of 755 mm Hg. If the wet O2 gas formed occupies a volume of 6.22 L, the number of grams of O2 formed is ________
g. The vapor pressure of water is 23.8 mm Hg at 25 °C.
Mass of O₂ formed = 7.84 g
Further explanationGiven
Reaction
2KClO₃(s) ⇒2KCl(s) + 3O₂(g)
P water = 23.8 mmHg
P tot = 755 mmHg
V = 6.22 L
T = 25 + 273 = 298 K
Required
mass of O₂
Solution
P tot = P O₂ + P water
P O₂ = P tot - P water
P O₂ = 755 - 23.8
P O₂ = 731.2mmHg = 0.962 atm
Moles O₂ :
Ideal gas law :
n = PV/RT
n = 0.962 x 6.22 / 0.082 x 298
n = 0.245
Mass O₂ :
= mol x MW
= 0.245 x 32
= 7.84 g
how are volcanologist and meteorologist similar and different?
Answer:
They are different because one is someone who studies volcanoes and the other is someone who studies weather
Explanation:
what is the percent chance that the offspring will be dwarf plants with yellow fruit
Answer:
Yellow fruit and dwarf vines are recessive traits in tomatoes. Red fruit and tall vines are dominant. Complete a Punnett square and answer the questions for a completely dominant red and tall plant crossed with a heterozygous red and dwarf plant.
Explanation:
What is the product of the unbalanced combustion reaction below?
Answer: A
Explanation:
Answer:
C
Explanation:
because the combustion reaction produce vapor water and CO2
The wastewater produced by offices is called __
Answer:
sullage or grey water
Explanation:
sources include: sinks, showers, baths, washing machines, dishwashers and no not toliets.
2. All elements are composed of extremely small particles called
Answer:
Atoms
Explanation:
A 10 wheeler truck collides with a car. Who is more likely to be hurt: the driver of the car or the driver of the truck? please justify your answer.
THANK YOU ت︎
Answer:
The driver in the car because a truck is a bigger vehicle and the impact of a truck to a car is more damaging than a car to a truck. Weight difference is the key I think.
Explanation:
What are two ways to describe concentration? How do they differ from one another?
Answer:
no .........................
PLEASE HELP! this is the last section and I cant figure it out. any assistance would be greatly appreciated
Reaction of galvanic cell
Further explanationGiven
Redox reaction between Zn and Mg
Required
Half reaction
Potential of the cell
Solution
Zn²⁺ + 2e -> Zn E ° = -0.76 V
Mg²⁺ + 2e -> Mg E ° = - 2.37 V
The higher E ° of the cell will act as the positive pole/cathode
Electrode Zn as a cathode (reduction) and Mg as an anode (oxidation) (E ° of Zn cells is greater than Mg)
Half reaction
Cathode: Zn²⁺ + 2e ⇒ Zn E ° = -0.76 V
Anode: Mg ⇒ Mg²⁺ + 2e E ° = +2.37 V
------------------------------------------------- ----------- +
Cell reaction: Zn²⁺ + Mg ---> Zn + Mg²⁺ E ° cell = +1.61 V
The reaction occurs spontaneously in the absence of an electric current, thus including galvanic cells/voltaic cells
Toxic chemicals in drinking water usually are reported and a safety level specified in units of parts per million (ppm) by mass. What is the molar concentration of arsenic in a water sample that has 1 ppm arsenic (As)
Answer:
The molar concentration of water sample that has 1 ppm arsenic is 1.33 * 10⁻⁵ M
Explanation:
1 parts per million (ppm) means 1 part of solute in a million parts of solution.
Since 1 million, 10⁶ mg = 1 kg, 1 ppm = 1 mg/kg
The density of water = 1.0 kg/L, therefore, the volume of 1 kg of water = 1 L
Hence, 1 ppm = 1 mg/kg = 1 mg/L
molar mass of arsenic = 75 g/mol
1 mg of arsenic = 10⁻³ g or 0.001 g
number of moles of arsenic in 0.001 g of arsenic = 0.001 g / 75 g/mol = 1.33 * 10⁻⁵ moles
Molar concentration = 1.33 * 10⁻⁵ mol / 1 L = 1.33 * 10⁻⁵ M
Therefore, the molar concentration of water sample that has 1 ppm arsenic is 1.33 * 10⁻⁵ M
Willie pushed on the cart with 1000 newtons of force. James pulled
on a rope attached
to the cart with 500 newtons of force. Piff pushed on the cart with 400
newtons. What will happen to the cart and why?
Answer:
Sxr
Explanation:
Rtxrcrctvucy
animal and Plant Cells Worksheet Word
Answer:
u didnt give a worksheet
Explanation:
What is the completed balanced reaction for the replacement Al×H2SO4
Answer:
2 Al(s) + 3 H₂SO₄(aq) ⇒ Al₂(SO₄)₃(aq) + 3 H₂(g)
Explanation:
Let's consider the unbalanced equation for the single replacement reaction between Al and H₂SO₄.
Al(s) + H₂SO₄(aq) ⇒ Al₂(SO₄)₃(aq) + H₂(g)
We will begin balancing S atoms by multiplying H₂SO₄ by 3.
Al(s) + 3 H₂SO₄(aq) ⇒ Al₂(SO₄)₃(aq) + H₂(g)
Then, we balance Al atoms by multiplying Al by 2.
2 Al(s) + 3 H₂SO₄(aq) ⇒ Al₂(SO₄)₃(aq) + H₂(g)
Finally, we get the balanced equation by multiplying H₂ by 3.
2 Al(s) + 3 H₂SO₄(aq) ⇒ Al₂(SO₄)₃(aq) + 3 H₂(g)
Which combination of variables will make an experiment the most reliable? A. Once controlled variable and many experimental variables. B. Two controlled variables C. Two experimental Variables D. One dependent variable and one experimental variable
Answer:
D. One dependent variable and one experimental variable
Explanation:
The experimental variable is defined as an independent variable which can be manipulated during an experiment in order to find out its impact or influence on the dependent variable.
The dependent variable refers to a variable that changes when an experimental or independent variable is manipulated.
Every experiment must have at least one experimental variable and one dependent variable in order to yield any meaningful result.
why is polarity an important factor when determining how molecules interact?
Answer:
Water's polarity allows it to dissolve other polar substances very easily. When a polar substance is put in water, the positive ends of its molecules are attracted to the negative ends of the water molecules, and vice versa.
Explanation:
Answer/Explanation:
When a polar substance is put in water, the positive ends of its molecules are attracted to the negative ends of the water molecules, and vice versa. Because molecular polarity results from the VECTOR sum of the individual bond dipoles. Water's polarity allows it to dissolve other polar substances very easily.
what type of reaction is Au2S+H2---> 2Au+H2S
Answer:
single replacement reaction is type of reaction is Au2S+H2---> 2Au+H2S.
100 POINTS!!! ANSWER ASAP
Answer:
1eV
Explanation:
Answer:
1ev
Explanation:
what are the 3 receptors
Answer:
Where’s the image?
Explanation:
Diseases are classified into _______ and _____ based on their duration.
Answer:
communicable and non-communicable?
In the reaction of solid copper with silver nitrate, solid silver and copper (II) nitrate form. How many grams of solid silver will form if 24.58 g of solid copper are used?
Answer:
83.4g
Explanation:
The reaction expression is given as:
Cu + 2AgNO₃ → Cu(NO₃)₂ + 2Ag
Mass of copper = 24.58g
Unknown:
Mass of silver produced = ?
Solution:
To solve this problem, let us find the number of moles of the copper;
Number of moles = [tex]\frac{mass}{molar mass}[/tex]
Molar mass of Cu = 63.6g/mol
Number of moles = [tex]\frac{24.58}{63.6}[/tex] = 0.39mole
1 mole of Cu will produce 2 moles of Ag
0.39 mole of Cu will produce 0.39 x 2 = 0.77moles of Ag
Mass of Ag = number of moles x molar mass = 0.77 x 107.9 = 83.4g
What is the volume of 1.8 moles of O2?
Answer:
33.6 i think
Explanation:
There are only seven base units of the metric system.
Which of the below is NOT a base unit of the metric system.
A. K for temperature
B. kg for mass
C. V for volume
D. s for time
Explanation:
V is not an SI base unit. (C)
Volume can be expressed as m³ in units.
In turn, m is the SI base units for length.
Base your answer on the information below. The hydrocarbon 2-methylpropane reacts with iodine as represented by the balanced equation below. At standard pressure, the boiling point of 2-methylpropane is lower than the boiling point of 2-iodo-2-methylpropane. Explain the difference in the boiling points of 2-methylpropane and 2-iodo-2-methylpropane in terms of both molecular polarity and intermolecular forces.
Answer:
See explanation
Explanation:
The boiling point of a substance is affected by the nature of bonding in the molecule as well as the nature of intermolecular forces between molecules of the substance.
2-methylpropane has only pure covalent and nonpolar C-C and C-H bonds. As a result of this, the molecule is nonpolar and the only intermolecular forces present are weak dispersion forces. Therefore, 2-methylpropane has a very low boiling point.
As for 2-iodo-2-methylpropane, there is a polar C-I bond. This now implies that the intermolecular forces present are both dispersion forces and dipole interaction. As a result of the presence of stronger dipole interaction between 2-iodo-2-methylpropane molecules, the compound has a higher boiling point than 2-methylpropane.
what is the experiment to find the concentration
A titration is an experiment where a volume of a solution of known concentration is added to a volume of another solution in order to determine its concentration. Many titrations are acid-base neutralization reactions, though other types of titrations can also be performed.Aug 12,
A rigid vessel contains 2.5 mol of H2(g). How many grams of hydrogen are in the vessel.
Answer:
5 g of H₂ are contained in the vessel
Explanation:
A typical excersise of conversion:
We determine molar mass of H₂.
This is a dyatomic molecule, as molar mass of H is 1g/mol, molar mass of H₂ will be 2g/mol.
Let's make the conversion of units:
2.5 mol . 2g/mol = 5 g
5 g of H₂ are contained in the vessel
Mass of hydrogen in the vessel = 5 grams
Number of moles:The number of moles is defined as the given mass over molar mass.
[tex]\text{Number of moles}=\frac{\text{Given mass}}{\text{Molar mass}}[/tex]
Given:
Number of moles= 2.5 mol
To find:
Mass of hydrogen=?
Molar mass of hydrogen =2g/mol
On substituting the values in the given formula we will get:
[tex]\text{Number of moles}=\frac{\text{Given mass}}{\text{Molar mass}}\\\\\text{Given mass}=\text{Number of moles}*\text{Molar mass}\\\\\text{Given mass}=2.5 mol* 2g/mol\\\\\text{Given mass}=5 g[/tex]
Thus, mass of hydrogen in the vessel is 5 grams.
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HELP!!!
How many grams of tomatoes are equivalent to 1.30 pounds of tomatoes? (1 lb = 453.6 g)
If you can please show me how you solved it. Please and Thank you
Answer: with dog figs- it is 590
With decimals it is 589.68
Explanation:
Which activity is an example of a scientist using creativity?
a scientist exploring evidence from other fields of science to support findings
a scientist transferring data from one experiment into the data analysis from a second experiment
a scientist repeating an older experiment with the latest technology to verify the original findings
a scientist using the latest graphing software to analyze and present the research
A scientist exploring evidence from other fields of science to support findings is an example of a scientist using creativity.
What is creativity?Creativity is a mental cognitive ability that involves the creation and/or discovery of a hidden process.
In science, creativity refers to the application of mental skills to create new experimental designs and extrapolate findings.
In conclusion, a scientist exploring evidence from other fields of science to support findings is an example of a scientist using creativity.
Learn more about creativity here:
https://brainly.com/question/26061350
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Compare and contrast protons and neutrons. Use A.C.E.
A= Answer
C= Cite Evidence
E= Expand
Which type of reaction is always spontaneous?
A. an exothermic reaction that has an increase in disorder
B. an exothermic reaction that has a decrease in disorder
C. an endothermic reaction that has an increase in disorder
D. an endothermic reaction that has a decrease in disorder
Answer:
A.) an exothermic reaction that has an increase in disorder.
Explanation:
got it correct (unit review test)