Answer:
D
Explanation:
Iithium and sodium are not in the same period
Write the symbol for every chemical element that has atomic number greater than 11 and atomic mass less than 24.8
Answer: You would write elements in period 1, 2, 3, and period 4 but you would stop at chromium
Explanation: It would have been too long for me to write every symbol
lodine is 80% 1271, 17% 1261, and 3% 1281. Calculate the average atomic mass of
iodine.
Isotopes are members of an element family that have the same number of protons but differ in the number of neutrons.
Atomic mass of Iodine = 126.86 amu
What is a isotope ?Isotopes are members of an element family that have the same number of protons but differ in the number of neutrons.isotopes are a type of atom, the smallest unit of matter that retains all of an element's chemical properties. Isotopes are chemical elements that have unique properties.Isotopes can form either spontaneously (naturally) through radioactive decay of a nucleus (emission of energy in the form of alpha particles, beta particles, neutrons, and photons) or artificially (via accelerators or neutrons in a nuclear reactor) by bombarding a stable nucleus with charged particles via accelerators or neutrons.The elements in nature have several types of isotopes
Atomic mass is the average atomic mass of all its isotopes
MassAtomic mass of Iodine = 126.86 amu atom X = mass isotope 1 . % + mass isotope 2.% + ... mass isotope n.%
Atomic mass of Iodine = 0.8 x 127 + 0.17 x 126 + 0.03 x 128
Atomic mass of Iodine = 101.6 + 21.42 + 3.84
Atomic mass of Iodine = 126.86 amu
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Select the correct answer.
Which statement is true?
Answer:
which statement is true what is the question
In a___ one line represents one pair of electrons being shared.
Choices:
A. Structural formula diagram
B. Dot diagram
C. Space-filling model
D. Ball-and-stick model
1. What is the definition of the word "petition"?
2. What was the name of the petition the delegates sent to King George 111?
Answer:
Definition: a formal written request, typically one signed by many people, appealing to authority with respect to a particular cause.
name was: Olive Branch petition. Why? = The Olive Branch petition was signed on July 8, 1775, and dispatched to Great Britain on two ships. King George III refused to even accept or consider the Olive Branch petition sent by the Continental Congress.
Explanation:
Qualitative Observations:
Quantitative
Observations:
Answer Qualitative Observations: were you gather info using your senses EX:(listening, touching ect.
qantitative observations: is a collection fo data or useing statistical and numerical analysis methods.
ASAP MULTIPLE CHOICE WILL MARK BRAINLIEST
Which symbol represents an ion?
4He
Ca
Mg
Na2+
The density of solid aluminum is 2.70 g/cm3. If a 1g piece of aluminum is dropped in a cup of water, what will happen to the aluminum? (The density of water is 1.00 g/cm3.)
Answer: c
Explanation: I took it
Answer:
IT WILL HOVER IN THE MIDDLE
Explanation:
Chromium-48 decays. After 6 half-lives, how much of the original nuclei would remain if we started with 600 g?
Answer:
1
Explanation:
2
With which group would group 18 most likely bond
Answer:
The noble gases (Group 18) are located in the right of the periodic table and were previously referred to as the "inert gases" due to the fact that their filled valence shells (octets) make them extremely nonreactivE
Explanation:
Is steel a compound or a mixture?
Chromium has a smaller atomic radius than iron. *
O
True
False
Answer:
False
Explanation:
Atomic radius is defined as the distance between the nuclei of 2 identical atoms that are bonded together
Now, from periodic tables, chromium has a calculated atomic radius of 1.66 Å while iron has a calculated atomic radius of 1.56 Å
Thus, chromium has a bigger atomic radius than iron.
So the statement is false.
How much hear must be obsorberd by 375.0 grams of water to raise its temperature from 10.0c to 35.0c? The specific heat capacity of water is 4.186 J/gC.
HELP DUE TOMORROW!!! ASAP
Answer:
The heat absorbed by water is 39243.75 J.
Explanation:
Given data:
Mass of water = 375.0 g
Heat absorbed by water= ?
Initial temperature = 10.0°C
Final temperature = 35.0 °C
The specific heat capacity of water = 4.186 j/g.°C
Solution:
Specific heat capacity:
It is the amount of heat required to raise the temperature of one gram of substance by one degree.
Formula:
Q = m.c. ΔT
Q = amount of heat absorbed or released
m = mass of given substance
c = specific heat capacity of substance
ΔT = change in temperature
ΔT = T2 - T1
ΔT = 35°C - 10°C
ΔT = 25°C
Q = m.c. ΔT
Q = 375.0 g× 4.186 j/g °C × 25°C
Q = 39243.75 J
The heat absorbed by water is 39243.75 J.
Is a microwave oven ac or dc
Answer:
Microwave Ovens run on AC Input from the power supply.
Answer:
Its an AC
Explanation:
microwave ovens run on AC Input from the power supply.
In what type of reaction or process does heat flow into the system?
combustion
exothermic
condensation
endothermic
The reactions in which flow of heat takes place into the system is known as endothermic process.
What is heat flow?Heat flow is a process in which transfer of heat takes place from one system to other or from outside to inside or vice-versa.
In in any chemical reaction for the completion of reaction if we have to absorb heat or flow of heat takes place from the outside into the system then that reaction is known as endothermic reaction.
Hence resultant process will be endothermic.
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Answer D. endothemic
Explanation: just took the quiz
ASAP MULTIPLE CHOICE WILL MARK BRAINLIEST
What is the mass number of an element equal to?
number of protons plus number of neutrons
number of electrons plus number of protons
number of protons
number of isotopes
Which paragraph from the article explains why the ultracool dwarf star discovery is so
significant to the search for other signs of life?
The system's host star, called TRAPPIST-1, is what is known as an ultracool dwarf. It is about
one-tenth the size of our sun and just a bit bigger than Jupiter.
Going forward, the authors plan to use even more powerful telescopes to analyze the
TRAPPIST-1 system. The Hubble Space Telescope will point its powerful lens toward the
ultracool dwarf star.
O "Systems around these tiny stars are the only places where we can detect life on an Earth-
sized exoplanet with our current technology," Gillon said in a statement. "If we want to find
life elsewhere in the Universe, this is where we should look."
O Ultracool dwarfs make up about 15 percent of the astronomical objects in our immediate
neighborhood, but until now, no one had ever discovered a planet orbiting one.
Answer:
It is ultracool dwarfs make up about 15% of the astronomical objects.................blah blah blah
Explanation:
took test
__ P4(s) + __ O2(g) → __ P4O10(s) To balance this reaction equation, first write correct formulas for the reactants and products, leaving the stoichiometric coefficients blank. We will balance P first. How many P4 molecules are needed to balance P for each P4O10?
Answer:
P4(s) + 5 O2 (g)→ P4O10
Explanation:
If we desire to write a balanced chemical reaction equation, the rule of thumb is simple; the number of atoms of each element on the right hand side of the reaction equation must be the same as the number of atoms of the same element on the left hand side of the reaction equation. Once this condition is satisfied, the reaction equation is said to be balanced.
As we can see, we need one mole of P4 and five moles of O2 to produce one mole of P4O10.
The balanced reaction for the combustion of phosphorus (P₄) to form phosphorus pentoxide (P₄O₁₀),
P₄(s) + 5O₂(g) → P₄O₁₀(s)
So, 1 P₄ molecule is needed to balance the number of phosphorus atoms for each P₄O₁₀ molecule.
A balanced equation is a chemical equation in which the number of atoms of each element on the reactant side is equal to the number of atoms of the same element on the product side. In other words, the law of conservation of mass is satisfied, meaning that no atoms are created or destroyed during the chemical reaction.
The coefficients (numbers in front of the chemical formulas) in a balanced equation represent the relative proportions of each reactant and product involved in the reaction. This ensures that the total mass of the reactants is equal to the total mass of the products in a chemical reaction.
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What happens to mass in an isolated system?
A) mass cannot enter or exit an isolated system
B) mass can exit but not enter an isolated system
C) mass can enter and exit an isolated system
D) mass can enter but not exit an isolated system
Answer:
A) mass cannot enter or exit an isolated system
Explanation:
An Isolated system is both insulated and sealed. No matter or energy can neither escape into the surroundings nor enter from the surroundings
Answer: A. mass cannot enter and exit an isolated system
Explanation: just took the quiz
Which of the following produces a chemical change?
O A. Boiling water
B. Burning candle wax
O C. Cooling molten lava
O D. Grinding iron into powder
Option B= Burning candle wax
Answer:buning candle wax B
Explanation:
A P E X
can someone just help me?? I'm literally so confused on this. this is on electron configuration. the teacher tried to explain to me multiple times but i still don't understand
Answer:
you have to fill each boxes with upwards arrow first (↑) and followed by downwards arrow (↓) according to each element's atomic number
40 points Plz Help me
Safety in the lab has to be a priority at all times when doing an investigation. Describe how you demonstrated good safety practices by using goggles during the lab. Why was it important for you to wear goggles during the lab?
Answer:
so the chemical doesn't get in ur eyes
Explanation:
Which sample of matter is a single substance
A air
B ammonia gas
C hydrochloric acid
D Salt water
Answer:
B) Ammonia gas
Explanation:
Ammonia gas: It consists of only one molecule namely ammonia throughout the substance so it is a pure single substance.
I need to write the definition with an example what it means.the word is opaque
Answer: opaque means not able to see through. An example is that a window is not opaque because you can see through it, but a rock is opaque.
Answer:
Opaque Definition below:
Explanation:
not able to be seen through; not transparent.
Hope it helps :)
When a nucleus breaks up to gain a more stable ratio of protons and neutrons
a
radiation poisoning
b
radioactive tracing
c
radioactive dating
d
radioactive decay
Bob rides his motorcycle with a constant speed of 116 km/h. How far can he travel in 1 hour?
Answer:
116 km...
Explanation:
as mentioned in the question, speed is constant....as it is clearly given the speed is 116 km per hour....so it will go 116km in an hour.
1. When the velocity of an object changes, it is acted upon by a(n)
deceleration.
inertia.
momentum.
force.
Answer:
when the velocity of an object changes,it is acted upon by an external force
When the velocity of an object changes, it is acted upon by a force. Therefore, option D is correct.
What causes a change in velocity explain ?Forces have an impact on how objects move. They can cause motion; they can also slow, stop, or change the direction of motion of an already moving object.
We can say that forces cause changes in velocity because they cause changes in an object's speed or direction. Keep in mind that acceleration is defined as a change in velocity.
Because velocity is a vector quantity, the given statement is correct. It is affected by both magnitude and direction. When one or both of them change, the velocity changes as well.
Thus, When the velocity of an object changes, it is acted upon by a force, option D is correct.
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length is a fundamental quantity. give reason.
Answer:
Explanation:
There is a fundamental length, the Planck length. It is the length that light (a photon) travels in a unit of time called the Planck time and conforms to the way to measure length in general, as given by the equation
L = ct
Where L is length (or distance), c the speed of light (3 X 10^8 meters/sec), and t the time the light travels in. The Planck length is exceedingly small (magnitude 10^-35 meters because the Planck time is short (10^-44 sec)
The Planck length, or any length based on the speed of light, is not subject to the imprecision we would find by measurement with a physical ruler, for example, because a ruler can expand or shrink or be bent or warped, etc.
Rather, length based on c (in a vacuum) is constant. This concept is another gift from Einstein’s theory of special relativity. It’s also the central concept in spacetime, though it would take some explaining for me to say why it is so.
Please helpppp ASAP !!!!Which phase changes require the addition of energy to happen, which phase changes require the removal of energy ?
Answer:
Evaporation
Explanation:
Evaporation involves a liquid becoming a gas and sublimation is the change of a solid directly to a gas. Phase changes require either the addition of heat energy or subtraction of heat energy .
In a complete reaction, 23 grams of sodium reacts with 37 grams of chloride , what is the total mass of sodium chloride produced (made)?
Answer:
60 grams NaCl
Explanation:
Because it is a complete reaction, the total mass of all the reactants is used. According to the law of conservation of mass, the same amount product should be produced as there was reactants. Add the mass together.
23+37= 60 g