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:
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
To express very large or very small numbers, scientists use what
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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gots another for you guys thanks inn advance
Answer:
c. the center of curvature of the two sides of the lens
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
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
Magnesium occurs naturally in only three isotopes. ^24 Mg has an isotopic mass of 23.9850 amu and an abundance of 78.99%. ^25 Mg has an isotopic mass of 24.9858 amu and an abundance of 10.00%. Find the mass number of the last isotope of magnesium.
Can someone please explain how to solve this? *done mine the notes*
Answer:
25,98 amu and 11.01% abundance
Explanation:
1. Find the missing abundance
100 - 78.99 - 10 = 11.01 %
2. Using each mass and abundance and the periodic table for the Mg amu
And let Isotope = Mg
23.9850(78.99%) + 24.9858(10%) + Mg(11.01%) = 24.305 (100%)
Solve for Mg
Mg = 25,98
A gas has a volume of 4.25 m3 at a temperature of 95.0°C and a pressure of 1.05 atm. What temperature will the gas have at a pressure of 1.58 atm and a volume of 2.46 m3
Answer:
[tex]\boxed {\boxed {\sf 82.7 \textdegree C}}[/tex]
Explanation:
We are asked to find the temperature of a gas given a change in pressure and volume. We will use the Combined Gas Law, which combines 3 gas laws: Boyle's, Charles's, and Gay-Lussac's.
[tex]\frac {P_1V_1}{T_1}=\frac{P_2V_2}{T_2}[/tex]
Initially, the gas has a pressure of 1.05 atmospheres, a volume of 4.25 cubic meters, and a temperature of 95.0 degrees Celsius.
[tex]\frac {1.05 \ atm * 4.25 \ m^3}{95.0 \textdegree C}= \frac{P_2V_2}{T_2}[/tex]
Then, the pressure increases to 1.58 atmospheres and the volume decreases to 2.46 cubic meters.
[tex]\frac {1.05 \ atm * 4.25 \ m^3}{95.0 \textdegree C}= \frac{1.58 \ atm *2.46 \ m^3}{T_2}[/tex]
We are solving for the new temperature, so we must isolate the variable T₂. Cross multiply. Multiply the first numerator by the second denominator, then multiply the first denominator by the second numerator.
[tex](1.05 \ atm * 4.25 \ m^3) * T_2 = (95.0 \textdegree C)*(1.58 \ atm * 2.46 \ m^3)[/tex]
Now the variable is being multiplied by (1.05 atm * 4.25 m³). The inverse operation of multiplication is division, so we divide both sides by this value.
[tex]\frac {(1.05 \ atm * 4.25 \ m^3) * T_2}{(1.05 \ atm * 4.25 \ m^3)} = \frac{(95.0 \textdegree C)*(1.58 \ atm * 2.46 \ m^3)}{(1.05 \ atm * 4.25 \ m^3)}[/tex]
[tex]T_2=\frac{(95.0 \textdegree C)*(1.58 \ atm * 2.46 \ m^3)}{(1.05 \ atm * 4.25 \ m^3)}[/tex]
The units of atmospheres and cubic meters cancel.
[tex]T_2=\frac{(95.0 \textdegree C)*(1.58* 2.46 )}{(1.05 * 4.25 )}[/tex]
Solve inside the parentheses.
[tex]T_2= \frac{(95.0 \textdegree C)*3.8868}{4.4625}[/tex]
[tex]T_2= \frac{369.246}{4.4625} \textdegree C}[/tex]
[tex]T_2 = 82.74420168 \textdegree C[/tex]
The original values of volume, temperature, and pressure all have 3 significant figures, so our answer must have the same. For the number we calculated, that is the tenths place. The 4 in the hundredth place to the right tells us to leave the 7 in the tenths place.
[tex]T_2 \approx 82.7 \textdegree C[/tex]
The temperature is approximately 82.7 degrees Celsius.
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:
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
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.
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.
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.
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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 :-)
THIS 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
nước tự nhiên là chất hay hổn hợp
nước tự nhiên là chất đó bạn
How many moles of magnesium bromide are formed when 3.0 moles of magnesium reacts with 2.0 moles of bromine?
Mg+Br2 -> MgBr2
Answer:
Explanation:
Hello there, I think this is a limiting agent question.
When 3 moles of Mg is reacted with 2 moles of Br2, because of ratio, we just need 1.5 moles of Br2, so Mg is a limiting agent.
So 3 moles of Mg will make 3 moles of MgBr
Answer:
Use the given functions to set up and simplify
Mg+Br2→MgBr⋅2.
3=
2=
Mg+Br2→gBr⋅2=r2B+gM→MgBr⋅2
Explanation:
SORRY IF I AM WRONG HAVE A BLESS DAY :D
Solid solid soluton example
Explanation:
rice and rice coatssalt and sugarsand and mudwheat flour and corn flourthere 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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briefly explain how to separate a mixture of water, kerosene, sawdust and nahso4?
Answer:
Use filtration method lol.
Which type of bond and how many bonds would occur as carbon dioxide (CO2) is formed from carbon in Group IVA and oxygen in Group VIA?
three metallic bonds
two ionic bonds
four covalent bonds
one covalent bond
Four covalent bonds are formed as carbon dioxide (CO2) is formed from carbon in Group IVA and oxygen in Group VIA.
The periodic table is composed of eighteen groups and eight periods. The common thread that holds all the elements in a group is that they all have the same number of valence electrons in their atoms. The elements in the same period all have the same highest energy level.
Oxygen in group Group VIA has six valence electrons while carbon in group Group IVA has four valence electrons. Hence, the chemical bond in carbon dioxide CO2 must contain four covalent bonds as shown in the image attached to this answer.
https://brainly.com/question/13178080
Answer:
Four Covalent bonds
Explanation:
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
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
A researcher wants to conduct an experiment to see how the amount of breakfast a student eats
affects their performance in school. He makes 2 groups, one group consumes 300 calories in
the morning while the second group does not eat breakfast at all. After 2 weeks he compares
the students test scores and every student takes the same tests. Identify the following:
a. Control Group:
b. Independent Variable:
c. Dependent Variable:
The control group are the students who eat no breakfast. The independent variable is the consumption of breakfast. The dependent variable is the performance of students in school.
In an experiment, the control group is the group that did not receive the treatment. The treatment in this case is the consumption of breakfast. Hence the group that did not consume breakfast is the control group.
The independent variable is the variable that is being manipulated and its effect evaluated. The manipulated variable here is consumption of food.
The dependent variable is the variable that is being measured. In this case, it is the performance of students at school.
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cuantos gramos de soluto y solvente tendra 127 gramos de solición cuya concentración es 14% m/m ayuda para resolverlo
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A brick has a mass of 100 G and a volume of 25CM3 what is the density of the brick
Answer:
[tex]\boxed {\boxed {\sf 4 \ g/cm^3}}[/tex]
Explanation:
We are asked to find the density of a brick. Density is a substance's mass per unit volume. The formula for calculating density is as follows.
[tex]\rho= \frac{m}{v}[/tex]
The mass of the brick is 100 grams and the volume is 25 cubic centimeters.
m= 100 g v= 25 cm³Substitute the values into the formula.
[tex]\rho= \frac{ 100 \ g}{25 \ cm^3}[/tex]
Divide.
[tex]\rho=4 \ g/cm^3[/tex]
The density of the brick is 4 grams per cubic centimeter.
name four states of matter
Answer:
1. solid
2. liquid
3. gas
4. plasma
Explanation:
In physics, a state of matter is one of the distinct forms in which matter can exist. Four states of matter are observable in everyday life: solid, liquid, gas, and plasma.
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
Helppppp….. is this right?
Answer:
Yes, it is correct.
Explanation:
400 cm = 4 m
40 m = 40 m
0.4 km = 400m
Therefore, 400 cm < 40 m < 0.4 km
Answer:
Explanation:
400 centimeter....... smallest
0.4 kilometer .............. middlest
40 meter..................... greatest
