Answer:
So, in general, atomic radius decreases across a period and increases down a group. Across a period, effective nuclear charge increases as electron shielding remains constant.
Explanation:
Moving from left to right across a period, the atomic radius decreases. The nucleus of the atom gains protons moving from left to right, increasing the positive charge of the nucleus and increasing the attractive force of the nucleus upon the electrons.
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Can you convert this balanced equation into a nominative equation?
Answer:
yes you can
Explanation:
Name the compounds represented by the
following formulas.
a. Ca(NO2)2 c. (NH4)2Cr207
b. Fe(OH)3 d. CuCH3COO
Answer:
Canxi nito dioxit; Sắt oxit vàng; Amoni dicromat;đồng axitaxetic
Explanation:
What are the factors affecting chemical reaction??? 4 points.
Answer:
Surface areaTemperature Concentration Amount of catalyst usedWhat factors affect the strength of electric and magnetic forces?
Answer:
nature of the core material, strength of the current passing through the core
Explanation:
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HELP PLEASE I HAVE A TEST TODAY AND I DON'T UNDERSTAND ANY OF THIS...
265 kilojoules of energy are added to 150g of ice at 0 degrees C how many grams of water would boil away
Answer:
About 67 grams or 67.39 grams
Explanation:
First you would have to remember a few things:
enthalpy to melt ice is called enthalpy of fusion. this value is 6.02kJ/mol
of ice
it takes 4.18 joules to raise 1 gram of liquid water 1 degree C
water boils at 100 degrees C and water melts above 0 degrees C
1 kilojoules is 1000 joules
water's enthalpy of vaporization (steam) is 40.68 kJ/mol
a mole of water is 18.02 grams
we also have to assume the ice is at 0 degrees C
Step 1
Now start with your ice. The enthalpy of fusion for ice is calculated with this formula:
q = n x ΔH q= energy, n = moles of water, ΔH=enthalpy of fusion
Calculate how many moles of ice you have:
150g x (1 mol / 18.02 g) = 8.32 moles
Put that into the equation:
q = 8.32 mol x 6.02 = 50.09 kJ of energy to melt 150g of ice
Step 2
To raise 1 gram of water to the boiling point, it would take 4.18 joules times 100 (degrees C) or 418 joules.
So if it takes 418 joules for just 1 gram of water, it would take 150 times that amount to raise 150g to 100 degrees C. 418 x 150 = 62,700 joules or 62.7 kilojoules.
So far you have already used 50.09 kJ to melt the ice and another 62.7 kJ to bring the water to boiling. That's a total of 112.79 kJ.
Step 3
The final step is to see how much energy is left to vaporize the water.
Subtract the energy you used so far from what you were told you have.
265 kJ - 112.79 kJ = 152.21 kJ
Again q = mol x ΔH (vaporization)
You know you only have 152.21 kJ left so find out how many moles that will vaporize.
152.21 kJ = mol x 40.68 or mol = 152.21 / 40.68 = 3.74 moles
This tells you that you have vaporized 3.74 moles with the energy you have left.
Convert that back to grams.
3.74 mol x ( 18.02 g / 1 mol ) = 67.39 grams
what physical properties could be used to separate iron filings from table salt
Answer:
Iron is magnetic and Salt is non magnetic
So Salt dissolves in water and Iron doesn't
a student reacted 40 drops of an unknown amine with 20 drops of iodomethane in 2 ml of a suitable solvent mixture. after 15 minutes of reaction, a white precipitate formed. the precipitate was isolated and its melting point was recorded to be 178 °c. what could this precipitate be?
The compound formed is the quaternary ammonium salt N,N,N-trimethyl-1-phenylmethanaminium iodide.
Quaternary ammonium salts are formed when methyl iodide reacts with an amine. The quaternary ammonium salt is an ionic substance which often has a high melting point. Remember that the melting point of a substance can be used to identify the substance.
In this case, a student reacted 40 drops of an unknown amine with 20 drops of iodomethane in 2 ml of a suitable solvent mixture. after 15 minutes of reaction, a white precipitate formed. the precipitate was isolated and its melting point was recorded to be 178 °c. This precipitate must be N,N,N-trimethyl-1-phenylmethanaminium iodide (Benzyltrimethylammonium iodide) because it is a quaternary ammonium salt whose melting point is 178 °c.
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2. Water should not be used to put electrical fires?
Answer:
You should never throw water on an electrical fire because water conducts electricity and you could be electrocuted.
Please mark 4 brainliests
Someone pls help me I will make you brain
Answer:
A
Explanation:
I talked about it in Economic Geography and Earth Science, I rememBer this
Which of the following has electrons in a d orbital?
Mg
Si
Cr
Са
Ionic bonds form between which two types of elements?
Answer:
Ionic bonds usually occur between metal and nonmetal ions. For example, sodium (Na), a metal, and chloride (Cl), a nonmetal, form an ionic bond to make NaCl.
Explanation:
Answer:
metal and nonmetal ions
Explanation:
pleasssse help!
According to the ideal gas law, which will occupy a larger volume - 100 g of helium or 100 g of oxygen, if both are at the same temperature and pressure.
Answer:
Helium
Explanation:
The pressure of He gas would be greater than that of O2 gas
what the differenve between ionisation and dissociation
What is the least apporaiate hypothesis for Eric to make?
Answer:
Where's the questions?
which type is every one in this picture: pure substance or mixture?
Answer:
1,2,3,4,8,9,10,12,14,15 and 16
Explanation:
Coz they have different kinds (colours) of atoms
The rest are pure substances,
I'm not so sure though, double check after this
I need help pleaseeee
is a skateboard matter or no matter
Answer:
it is matter cus everything is made up of matter
Explanation:
Answer: yes
Explanation:
Matter makes up everything
What volume (in L) of 1.10 M FeCl₃ would be required to obtain 0.700 moles of Cl⁻ ions?
0.636 liters of the 1.10 M FeCl₃ solution to obtain 0.700 moles of Cl⁻ ions.
Thus, Volume (L)= moles/ concentration. 0.700 moles of Cl⁻ ions and the concentration of the FeCl₃ solution is 1.10 M, you can plug in these values to calculate the volume.
Volume (L) = 0.700/ 1.10 M,
Volume (L)= 1.10M/ 0.700moles
Volume (L) = 0.700/ 1.10 ≈ 0.636 L
Therefore, approximately 0.636 liters of the 1.10 M FeCl₃ solution to obtain 0.700 moles of Cl⁻ ions.
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why is each individual produced by sexual reproduction unique?
Answer:
During sexual reproduction the genetic material of two individuals is combined to produce genetically diverse offspring that differ from their parents. The genetic diversity of sexually produced offspring is thought to give species a better chance of surviving in an unpredictable or changing environment.
Which of these statements is not true?
A. Atoms of the same element can have different masses
B. The nucleus of an atom has a positive charge
C. Atoms of isotopes of an element have different numbers of protons
D. Atoms are mostly empty space
Option 5
Answer:
c.
Explanation:
They can have different neutron numbers, not proton numbers. If they were to have different proton numbers it would be classified as a different element.
Where is a mid-ocean ridge exposed above sea level?
Question 11 options:
Himalaya Mountains
Mariana Trench
The Big Island of Hawaii
Iceland
Answer:
ice land should be it
Explanation:
Answer:
Iceland is the answer.
Explanation:
2. DEFINE CHEMICAL BOND IN YOUR OWN WORDS.
Answer:
chemical bond are bonds that are strong lasing between chemicals and irons and morecles
hello can anyone help me with this question thx
Answer:
A. W and X
Explanation:
Because W have just one valence electron, and X have 7, so it means that W will give its electron to X and that's the definition of an ionic bond
Which grouping shows a decrease in Intermolecular
Forces of Attraction?
A) gas, liquid, solid B) liquid, solid, gas
C) solid, liquid, gas D) solid, gas, liquid
Answer:
C) solid, liquid, gas
Explanation:
Which grouping shows a decrease in Intermolecular
Forces of Attraction?
A) gas, liquid, solid B) liquid, solid, gas
C) solid, liquid, gas D) solid, gas, liquid
the further the particles are from each other, the less the intermolecular attraction they are farthest in a gas, then a liquid, and closest in a solid
Joshua loads a water balloon into a giant sling shot, pulls it back, and launches the balloon toward a target. The balloon misses the target by 3 feet, so he decides to try again. Which part of the process demonstrates an application of force?
Someone pls help me I will make you brain
Answer:
It is true answer. Ozone = O3
Use the following image to answer the following questions. A student was performing an experiment using two identical cups made of styrofoam. The student had Cup A holding water at 90℃ and Cup B holding water at 20℃. The student then put an Aluminum Bar into each cup that was touching the water. As time passed, the student noticed that the temperature of the water in Cup A and Cup B began to change. Question:
A. Predict what will happen to the temperature of the water in Cup A and Cup B after 1 hour has passed.
B. Explain and give evidence for what type of heat transfer is occurring between the 2 cups.
Whoever answers my question gets brainliest
Answer:
The water will eventually become the same temature (A)
How do you know where something fits on the electromagnetic spectrum? I currently have the Hz but do I need to convert that into something else?
Answer:
can oxygen exist as a liquid and solid
Which subatomic particle has a positive charge?
Question 1 options:
all particles
neutron (n0)
proton (p+)
electron (e-)
Question 2 (2 points)
What information does the atomic mass of an element provide?
Question 2 options:
the difference between the number of protons and electrons (p - e)
the number of isotopes
the sum of electrons and protons in an atom (e + p)
the number of protons and neutrons in an atom (p + n)
Question 3 (2 points)
What is the atomic number of an atom?
Question 3 options:
the number protons and neutrons
the number of protons
the number of neutrons
the number of electrons and neutrons
Question 4 (2 points)
What is H2O (water) classified as?
Question 4 options:
a diatomic molecule
an atom
an element
a molecule
Question 5 (2 points)
Which property is a physical property?
Question 5 options:
easy to digest
becomes moldy quickly
does not burn
malleable (the quality of something that can be shaped into something else without breaking )
Question 6 (2 points)
What state of matter has a defined volume but undefined shape?
Question 6 options:
solids and liquids
liquids
liquids and gases
gases
Question 7 (2 points)
Which statement best describes the difference between a physical change and a chemical change?
Question 7 options:
A chemical change does not result in a new substance being formed, whereas a physical change does.
A chemical change results in a new element being formed, and a physical change results in a new compound being formed.
A physical change produces a new element, and a chemical change results in a bond breaking between atoms.
A physical change is a change from one state of matter to another; a chemical change results in a new substance formed.
Question 8 (2 points)
Where are nonmetals located in the periodic table?
Question 8 options:
in the middle
along the bottom
along the upper left side
along the upper right side
Question 9 (2 points)
The elements fluorine (F), chlorine (Cl), and Iodine are all part of the same ____________________ on the periodic table.
Question 9 options:
period
group
Question 10 (2 points)
How are elements arranged on the periodic table?
Question 10 options:
atomic mass (# of protons and neutrons)
atomic number (# of protons)
density
boiling point
Help please ill give 100 points
Answer:
SCORE WARNING ! ! ! (JUST FINISHED MY TEST AND GOT A B IM NOT SURE WHICH ONE WAS INCORRECT btw it was the K12 8th grade test)
1. C / Proton (p+)
2. D / the number of protons and neutrons in an atom (p + n)
3. B / the number of protons
4. D / a molecule
5. B / becomes moldy quickly
6. D / gases
7. D / A physical change is a change from one state of matter to another; a chemical change results in a new substance formed.
8. D / upper right side
9. B / group
10. B / atomic number (# of protons)
Explanation:
I just took the test
The positively charged subatomic particles are called protons. The mass number of an atom is the sum of number of protons and neutrons and the atomic number is the number of protons.
What is an atom?An atom is the basic unit every substances. It is made up of subatomic particles electrons, protons and neutrons. The positively charged particles are called protons. Whereas electrons are negatively charged.
The atomic number is the number of protons and the mass number indicates the sum of number of protons and neutrons.
Water can be classified as a diatomic molecule formed from two hydrogens and one oxygen atom. Among the given, malleability is a physical property. It is the ability to change the shape and size of metal blocks.
Liquids has definite volume but does not have a defined shape. They assume shape of the container.A physical change is a change from one state of matter to another; a chemical change results in a new substance formed.
Nonmetals are located in the side upper right side of periodic table. Metals are covered in left and middle portion. The elements F, Cl are in same group. All the elements are arranged in periodic table based on their atomic number.
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Potassium and bromine combine to make KBr. What is the name of this compound?
potassium bromine
potassium bromide
bromine potassium
bromine potassiumide