Answer:
Friction always slows a moving object down. ... Friction can be a useful force because it prevents our shoes slipping on the pavement when we walk and stops car tyres skidding on the road. When you walk, friction is caused between the tread on shoes and the ground. This friction acts to grip the ground and prevent sliding.
What makes an atom radioactive?
Answer:
The unstable nucleus of radioactive atoms emit radiation.
Explanation:
When the atoms of an element have extra neutrons or protons it creates extra energy in the nucleus and causes the atom to become unbalanced and unstable, or radioactive.
(https://www.epa.gov/radtown/radtown-radioactive-atom-activity-4-atomic-stability)
Answer:
When the atoms of an element have extra neutrons or protons it creates extra energy in the nucleus and causes the atom to become unbalanced or unstable. Whether radioactive elements can become stable and if so, how. The unstable nucleus of radioactive atoms emit radiation. ... This process is called radioactive decay.
Explanation:
can any one tell me same for ALCL3 I need it urgently plzzz
Lets Form bonds
Al=2,8,3
Lets Write actual configuration or modern
[tex]\\ \sf\longmapsto 1s^22s^22p^63s^3[/tex]
It has valency +3Cl:-2,8,7Let's write configuration
[tex]\\ \sf\longmapsto 1s^22s^22p^63s^23p^5[/tex]
It has valency -1Now Criss cross valency (Refer to attachment)
We get
[tex]\\ \sf\longmapsto AlCl_3[/tex]
A sample of brass weighing 1.203g was analyzed. The zinc in the alloy was reacted with 35.123g of HCl in excess, according to the balanced equation:
Zn (s) + 2HCl(aq) - > H2(g) + ZnCl2 (aq)
After all the zinc reacted, the mass of the remaining solution weighed 36.309g
What was the mass of H2 produced?
What mass of Zn reacted?
What was the percentage of Zn (by mass) in the alloy?
The number of moles of reactants and products can be used to obtain the mass of products formed. The results obtained are as follows;
The mass of hydrogen produced is 0.0174 gramsThe mass of zinc produced is 0.5688 gramsThe percentage by mass of zinc in the brass alloy is 47.3 %The question says that HCl was in excess. It means that after the reaction, we will have unreacted HCl(aq) and ZnCl2(aq) in the remaining solution.
Hence;
Mass of ZnCl2(aq) formed = 36.309g - 35.123g = 1.186g
Number of moles ZnCl2(aq) formed = [tex]\frac{mass of ZnCl2(aq) formed}{molar mass of ZnCl2}[/tex]
[tex]\frac{1.186g}{136.286 g/mol}[/tex] = 0.0087 moles
From the reaction equation;
[tex]Zn (s) + 2HCl(aq) - > H2(g) + ZnCl2 (aq)[/tex]
To obtain the amount of Zn reacted
1 mole of Zn yields 1 mole of ZnCl2
x moles of Zn yields 0.0087 moles of ZnCl2
x = 0.0087 moles of Zn
a) 1 mole of Zn yields 1 mole of H2
0.0087 moles of Zn yields 0.0087 moles of H2
Mass of H2 = 0.0087 moles of H2 * 2 g/mol = 0.0174 grams
b)
Mass of Zn reacted = 0.0087 moles of Zn * 65.38 grams/mole = 0.5688 grams
c)
Percentage of Zn in the alloy = 0.5688 grams/1.203g * 100 = 47.3 %
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cuantos gramos de soluto y solvente tendra 127 gramos de solición cuya concentración es 14% m/m ayuda para resolverlo
banetshegtsjegsgeheb
If zinc has an atomic number of 30 and a mass number of 65 what is the correct number of protons neutrons and electrons ?
Answer:
protons 30
neutrons 35
electrons 30
!!DUE TODAY, NEED HELP ASAP!!
A student measured the masses of some aluminum and copper cylinders of different volumes. The data is displayed below:
Aluminum: Copper:
Volume (mL)
Mass (g)
Volume (mL)
Mass (g)
3.7
9.99
1.8
16.02
6
16.2
2.3
20.47
8.5
22.99
3.5
31.15
10.74
29
4.2
37.38
15
40.5
5.8
51.62
On graph paper graph the data above on ONE graph. Use the graph paper so the longer side is your y-axis.
Use up the majority of the graph paper. Do not make a small graph!
Use a ruler/straight edge so you graph is neat.
You will need to plot the points for each substance and create a double line graph. When connecting your points for each substance, continue the lines past the plotted points.
Be sure to include a key to identify the substances.
Make your X-axis volume(mL) and your Y-axis mass(g)
Look at the numbers for both substances when creating your scales. You will most likely have a different scale for mass and volume. What is the lowest number? What is the highest number? What does it make sense to go by?
Calculate the density of each metal.
Aluminum:_________________________ Copper:________________________
What happens to the mass of the copper at the volume increases from 6 to 8mL?
Which sample is more dense? How does the graph show you this?
Answer: The data are not arranged in a useful pattern. I arranged them as best I could and made a graph in Excel for demonstration.
Explanation: The data are plotted with mass on the x axis and volume on the y. Add a key to identify the top line as CU and the bottom as Al.
The density of Cu is 8.9 g/ml and 2.70 for Al.
The mass of copper increases by 17.8 grams going from 6 to 8 ml. (8.9 g/ml)*(2 ml) = 17.8 grams.
Copper is more dense. c The graph shows that for the same volumes, copper has the higher mass.
Isotope ?-1 has an atomic mass of 1.
99.985% of all atoms of element ? are of this
form.
Isotope ?-2 has an atomic mass of 2
0.015% of all atoms of element ? are of this form.
Answer: Isotope-1: Hydrogen (H)
Isotope-2: Deuterium (H)
Explanation: The periodic table shows that the smallest element in hydrogen (H), at an average atomic weight of 1.008. Hydrogen-1 has one proton, one electron, and no neutrons, which adds to 1 AMU. Hyrogen-2 is an isotope of hydrogen that contains 1 neutron in addition to the proton, bringing the mass to 2 AMU. It is only at 0.0156% abundance on Earth and is given the name Deuterium, sometimes refered to as "heavy water" when incorporated into a water molecule. A third isotope has 2 neutrons, and is called Tritium.
Vapor pressure of any liquid _______. A. increases with increases in temperature B. increases with decreases in temperature C. is not affected by changes in temperature D. increases with increases in volume of the liquid E. None of the Above
Answer:
increase with increases in temperature
Explanation:
please mark me brainleast
HELP! Fill in the blanks:
The net charge of an atom is equal to the difference between the_____
in the atom's nucleus and the_____
Answer:
I don't know
Explanation:
is today your test
what is sublimation
Explanation:
Sublimation is the conversion of a substance from the solid to the gaseous state without its becoming liquid. ... Freeze-drying of food to preserve it involves sublimation of water from the food in a frozen state under high vacuum. See also vaporization; phase diagram.
there are 3 isotopes of the element Gz: Gz-80,Gz-81,Gz-83. the average atomic mass of Gz is 82.74. what is the most abundant isotope of Gz? (please type the mass number only )
The most abundant isotope is Gz-83 because the average atomic mass of Gz is closer to 83.
The average atomic mass is defined as the weigthed mean of the isotopes.
The mass of the isotopes is 80, 81 and 83 uma, respectively.
As the average atomic mass (82.74uma) is closer to the atomic mass of Gz-83 than the mass of the other isotopes, you can interpretate that the most abundant isotope is Gz-83.
Learn more about average atomic mass in:
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What are the answers to these?
Answer:
1)physical change
Explanation:
2)chemical change
ANSWER QUICK PLEASE!!!! 25 POINTS
Acrylonitrile and ethyl acetate have the same boiling point: 77.2ºC. In one to two sentences, explain what outcome you would expect if a mixture of these two substances were distilled.
The two substances can never be separated by distillation because distillation depends on difference in boiling point.
Distillation is a separation method that depends on difference in boiling point between two substances.
Usually, the substance having a lower boiling point is collected first as the temperature is gradually raised. The substance having a higher boiling point then follows.
However, since the two substances have the same boiling point, they can not be separated by distillation because they will be converted to vapor simultaneously thereby making separation impossible.
Learn more: https://brainly.com/question/15946045
will mark brainliest if correct
Which methods separate a mixture according to the size of the particles?
a
filtration and chromatography
b
distillation and chromatography
c
filtration and evaporation
d
distillation and evaporation
Answer:
filtration and chromatography
Explanation:
I hope this will help you :-)
If an object has a mass of 43.23 g and a volume of 32.1 mL, what is its density? Show your work!
Answer: 1.34 g/ml
Explanation: Density is an objectives mass divided by it's volume:
(43.23 g)/(32.1 ml) =1.34 g/ml
briefly explain how to separate a mixture of water, kerosene, sawdust and nahso4?
Answer:
Use filtration method lol.
In your conversion from Milli- to Centi- units, would you move the decimal point to the left or the right?
Answer:
one unit to the left
Explanation:
cm are 10 times mm, so to convert you have to divide by ten
Examples
100 mm = 10,0 cm
0.50 mm = 0.05 cm
Please help me with this chemistry
Answer:
D=1.56g/mL
Explanation:
Density=m/v
D=14.06g/(24mL-15mL)
D=14.06g/9mL
D=1.56g/mL
Which of the following statements about alcohols is false?
A. Ethanol is soluble in water.
B. Ethanol has a higher boiling point than ethane.
C. Ethanol produces hydrogen when it burns.
D. None of these
Answer:
It's C. Ethanol produces hydrogen when it burns
When burned, ethanol produces water and CO2.
Describe the color change that would be observed in water in left hand beaker
Answer:
is there supposed to be a photo with this?
Explanation:
Help!! due tomorrow
.
Answer:
It's B. The molecules in the system have more kinetic energy than a solid.
gots another for you guys thanks inn advance
Answer:
c. the center of curvature of the two sides of the lens
An element has an atomic number of 16. An ion of this element has a 2-charge. How was the ion formed?
Answer: The answer is ‘a neutral atom gained 2 electrons’
Explanation: Because electrons are negatively charged and adding 2 extra would make the ion negatively charged by 2
Answer:
The answer to all the quiz questions are
Explanation:
1. Which statement describes the number of protons in each atom of an element?
*The number of protons is given by the atomic number, which increases by one moving from left to right across each row of the periodic table.*
2. An element has an atomic number of 16. An ion of this element has a 2– charge. How was the ion formed?
*A neutral atom gained 2 electrons.*
3. Rubidium has an atomic number of 37 and a mass number of 85. How many protons, neutrons, and electrons does an ion of rubidium with a 1+ charge have?
*37 protons, 48 neutrons, and 36 electrons*
4. There are three stable forms of neon: neon-20, neon-21, and neon-22. Which statement is true?
*Their atomic masses differ.*
5. Beryllium has an atomic number of 4. How many neutrons does the isotope beryllium-9 have?
*5*
Which of the following statements is not true about ecosystems?
a. A healthy ecosystem can support an unlimited number of life forms.
b. Predators play a role in balancing the earth's ecosystems.
c. People's activities can improve the health of an ecosystem.
d. The parts of an ecosystem depend on each other.
Answer:
A
Explanation:
though an ecosystem can support life forms,when they become over populated or unlimited there will be competition for food,Shelta and other basic necessities which will lead to many of these life forms dying
if you are asked to help the laboratory assistant in separating the mixture which method will you see?
Answer:
use secondary data. the normal method to use
What is the change of state in which a gas becomes a liquid?
Answer:
Condensation
Explanation:
Answer:
Condensation
Explanation:
When a gas changes to a liquid it is known as condensation. It happens when molecules in a gas slowly reduce their movement speed.
HOPE THIS HELPED
nước tự nhiên là chất hay hổn hợp
nước tự nhiên là chất đó bạn
Solid solid soluton example
Explanation:
rice and rice coatssalt and sugarsand and mudwheat flour and corn flourTHIS IS URGENT meant to be due today can someone help out please I’ll brainlist :)!
Hi,
These are the answers
•Question 6. B, Yogurt and sour milk
•Question 7. B, turn litmus paper red
•Question 8. B, used to find pH of a solution
•Question 9. A, names of products and reactants of a chemical reaction in words
•Question 10. B, feel slippery
Hope it help you. Pls mark brainliest if it helped you
To express very large or very small numbers, scientists use what
