Answer:
Mass = 5.24 g
Explanation:
Given data:
Number of atoms of Ca = 7.9×10²² atoms
Mass of Ca = ?
Solution:
First of all we will calculate the number of moles by using Avogadro number.
1 mole contain 6.022×10²³ atoms
7.9×10²² atoms × 1 mol /6.022×10²³ atoms
1.31 ×10⁻¹ mol
0.131 mol
Mass of Ca:
Mass = number of moles × molar mass
Mass = 0.131 mol × 40 g/mol
Mass = 5.24 g
Marianne designs an experiment involving electrically charged objects. She wants to know which objects will be attracted to a negatively charged balloon. Identify the test variable, the outcome variable, and the control variable for this experiment.
WILL GIVE BRAINIST
Answer:
When one object is rubbed against another, static electricity can be created. This is because the rubbing creates a negative charge that is carried by electrons. The electrons can build up to produce static electricity. For example, when you shuffle your feet across a carpet, you are creating many surface contacts between your feet and the carpet, allowing electrons to transfer to you, thereby building up a static charge on your skin. When you touch another person or an object, you can suddenly discharge the static as an electrical shock.
Similarly, when you rub a balloon on your head it causes opposite static charges to build up both on your hair and the balloon. Consequently, when you pull the balloon slowly away from your head, you can see these two opposite static charges attracting one another and making your hair stand up.
Materials
• Balloon
• An object made out of wool (such as a sweater, scarf, blanket or ball of yarn)
• Stopwatch
• A wall
• A partner (optional)
Preparation
• Blow up the balloon and tie off the end.
• Have your partner prepare to use the stopwatch.
Procedure
• Hold the balloon in a way that your hand covers as little of its surface area as possible, such as by using only your thumb and pointer finger or by gripping the balloon by its neck where it is tied off.
• Rub the balloon on the woolly object once, in one direction.
• Hold the balloon up on the wall with the side that was rubbed against the wool facing the wall, then release it. Does the balloon stay stuck on the wall? If the balloon stays stuck, have your partner immediately start the stopwatch to time how long the balloon remains bound to the wall. If the balloon does not stick, move to the next step.
• Touch the balloon to a metal object. Why do you think this is important to do?
• Repeat the above process but each time increase the number of times you rub the balloon on the woolly object. Rub the balloon in the same direction each time. (Do not rub the balloon back and forth.)
Observations and results
In general, did the balloon stick to the wall for a longer amount of time as you increased the number of times you rubbed the balloon on the woolly object?
Wool is a conductive material, which means it readily gives away its electrons. Consequently, when you rub a balloon on wool, this causes the electrons to move from the wool to the balloon's surface. The rubbed part of the balloon now has a negative charge. Objects made of rubber, such as the balloon, are electrical insulators, meaning that they resist electric charges flowing through them. This is why only part of the balloon may have a negative charge (where the wool rubbed it) and the rest may remain neutral.
When the balloon has been rubbed enough times to gain a sufficient negative charge, it will be attracted to the wall. Although the wall should normally have a neutral charge, the charges within it can rearrange so that a positively charged area attracts the negatively charged balloon. Because the wall is also an electrical insulator, the charge is not immediately discharged. However, because metal is an electrical conductor, when you rub the balloon against metal the extra electrons in the balloon quickly leave the balloon and move into the metal so the balloon is no longer attracted and does not adhere.
HOPE IT HELPS
PLEASE MARK ME BRAINLIEST
The test variables and the control variable and the outcome variables are Balloons, the electrical insulators, and resist electric charges flowing through them.
What are variables?When we brush a balloon against our head, the hair and balloon both develop opposing static charges. We can see how these two opposing static charges attract one another and make our hair stand up as the balloon is gently dragged away from our head.
When a balloon is rubbed to the wall, it will be attracted to the wall. Because the wall is an electrical insulator, the charge is not quickly discharged.
The excess electrons in the balloon immediately leave the balloon and go into the metal when it is rubbed against metal. As a result, the balloon is no longer attracted to the metal and does not adhere.
Therefore, Balloons, which act as electrical insulators and prevent the flow of electric charges, serve as the test, control, and outcome variables.
To learn more about variables, refer to the link:
https://brainly.com/question/29736640
#SPJ2
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
#SPJ1
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.
Learn more:
brainly.com/question/14464650
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
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:
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)
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:
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.
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
KOH + _co2 -_ксоз + _Н,0
Answer:
2KOH + 3co2 ------->2ксоз + 2Н20
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.
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)
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.
A silver cube with an edge length of 2.28 cm and a gold cube with an edge length of 2.75 cm are both heated to 82.8 ∘C and placed in 111.5 mL of water at 20.2 ∘C . What is the final temperature of the water when thermal equilibrium is reached?
Solution :
Given :
length of silver cube = 2.28 cm
length of gold cube = 2.75 cm
Initial temperature = 82.8°C
Volume of silver cube is
Volume [tex]$=(\text{edge length})^3$[/tex]
= [tex]$(2.28)^3$[/tex]
[tex]$= 11.8 \ cm^3$[/tex]
mass of silver cube
Mass, [tex]$m_s = \text{density} \times \text{volume} $[/tex]
= 10.5 x 11.8
= 123.9 g
Similarly, the volume of gold cube is
Volume [tex]$=(\text{edge length})^3$[/tex]
= [tex]$(2.75)^3$[/tex]
[tex]$= 20.79 \ cm^3$[/tex]
mass of gold cube
Mass, [tex]$m_g = \text{density} \times \text{volume}$[/tex]
= 19.3 x 20.79
= 401.247 g
Now
heat lost by silver and gold cube = heat gained by water
∴[tex]$m_g .c_g \Delta T + m_s .c_s \Delta T = m_w.c_w \Delta T$[/tex]
[tex]$m_g .c_g (82.8- T) + m_s .c_s (82.8- T) = m_w.c_w (T - 20.2)$[/tex]
[tex]$401.247 \times 0.1264 (82.8- T) + 123.9 \times 0.2386 (82.8- T) = 111.5 \times 4.184 (T - 20.2)$[/tex]
Now solving the equation
[tex]$50.71 (82.8- T) + 29.56 (82.8- T) = 466.51 (T - 20.2)$[/tex]
Final temperature, T = 31.27°C
What group number is Plutonium in and how do you know?
Answer:Actinide Group
Explanation:Plutonium is a member of the actinide group in the periodic table. Plutonium atoms have 94 electrons and 94 protons with 2 valence electrons in the outer shell. There are 150 neutrons in the most abundant isotope.
Diseases are classified into _______ and _____ based on their duration.
Answer:
communicable and non-communicable?
what is the percent composition of (NH4)2S?
if you can, include the problem shown pls
extra.
Mg(NO3)2
please don't just take the points please :(, do the problem
thank you <333
(NH₄)₂S
%N= 41.18%
%H =11.76%
%S=47.06%
Mg(NO₃)₂
%Mg=32.43%
%N=18.92%
%O=(64.86%
Further explanationGiven
(NH₄)₂S
Mg(NO₃)₂
Required
The percent composition
Solution
(NH₄)₂S MW=68 g/mol
%N=2. Ar N / MW (NH₄)₂S x 100%
%N= (2.14/68) x 100% = 41.18%
%H =(8.1/68) x 100%=11.76%
%S=(32/68)x 100%=47.06%
Mg(NO₃)₂ MW=148 g/mol
%Mg=(2.24/148)x100%=32.43%
%N=(2.14/148)x100%=18.92%
%O=(6.16/148)x100%=64.86%
which is an example of radiation?
Hot air rises and cool air moves in to take its place.
Heated water begins circulating in a fish tank.
Your car parked in the sun is hot when you return.
You burn your feet on a hot sidewalk on a sunny day.
Answer:
Heated water begins circulating in a fish tank.
Explanation:
Answer:
Heated water begins circulating in a fish tank.
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:
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
Please help me.
Thank you!
Answer: Positive
Explanation: Just a guess
Answer:
Positive
Explanation:
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,
: How are reefs impacted by disease?
Answer:
The frequency of coral diseases has increased significantly over the last 10 years, causing widespread mortality among reef-building corals. Many scientists believe the increase is related to deteriorating water quality associated with human-made pollutants and increased sea surface temperatures.
Explanation:
2. All elements are composed of extremely small particles called
Answer:
Atoms
Explanation:
animal and Plant Cells Worksheet Word
Answer:
u didnt give a worksheet
Explanation:
16.A mixture of carbon dioxide and hydrogen gases contains carbon dioxide at a partial pressure of 217 mm Hg and hydrogen at a partial pressure of 703 mm Hg. What is the mole fraction of each gas in the mixture?
XCO2 =
XH2 =
x CO₂ = 0.236
x H₂ = 0.764
Further explanationGiven
P CO₂ = 217 mmHg
P H₂ = 703 mmHg
Required
The mole fraction
Solution
Dalton's law :
The total pressure of a mixture of gases is equal to the sum of the partial pressures of the component gases
Can be formulated:
P tot = P1 + P2 + P3 ....
P tot for the mixture :
= 217 mmHg + 703 mmHg
= 920 mmHg
Mole fraction of each gas :
x CO₂ = 217 mmHg/920 mmHg = 0.236
x H₂ = 703 mmHg/920 mmHg = 0.764
Compare and contrast protons and neutrons. Use A.C.E.
A= Answer
C= Cite Evidence
E= Expand
What is the molarity of a solution with 1.43 moles of sodium chloride in 0.875 liters of solution?
1.63 M
General Formulas and Concepts:Math
Pre-Algebra
Order of Operations: BPEMDAS
Brackets Parenthesis Exponents Multiplication Division Addition Subtraction Left to RightEquality Properties
Multiplication Property of Equality Division Property of Equality Addition Property of Equality Subtract Property of EqualityChemistry
Unit 0
Reading a Periodic TableWriting CompoundsAqueous Solutions
Molarity = moles of solute / liters of solutionExplanation:Step 1: Define
1.43 mol NaCl (sodium chloride)
0.875 L solution
Step 2: Find M
Substitute [M]: x M = 1.43 mol NaCl / 0.875 LDivide: x = 1.63429 MStep 3: Check
Follow sig fig rules and round. We are given 3 sig figs.
1.63429 M ≈ 1.63 M
What is the volume of 1.8 moles of O2?
Answer:
33.6 i think
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: