4. Which elements have a completely full outermost energy level?
Answer:
Helium (He), neon (Ne), and argon (Ar), as group 18 elements, have outer electron shells that are full or satisfy the octet rule. This makes them highly stable as single atoms. Because of their non-reactivity, they are called the inert gases or noble gases.
Explanation:
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Write a balanced chemical equation for the standard formation reaction of gaseous hydrogen bromide (hbr)
[tex]\\ \sf\longmapsto H_2+Br_2\longrightarrow HBr[/tex]
Balanced equation[tex]\\ \sf\longmapsto H_2+Br_2\longrightarrow 2HBr[/tex]
On reactant side:-
H=2Br=2On products side
H=2Br=2The balanced chemical equation for the synthesis of hydrogen bromide is [tex]\rm H_2\;+\;Br_2\;\rightarrow\;2\;HBr[/tex].
What is a balanced chemical equation?The balanced chemical equation has been given as the reaction in which the number of atoms for each element on the product and the reactant side is equal.
The HBr has been formed with the reaction of the hydrogen and the bromine. The balanced chemical equation for the reaction has been:
[tex]\rm H_2\;+\;Br_2\;\rightarrow\;2\;HBr[/tex]
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What can you infer from the fact that nitrogen gas is useless to animals?
Answer:
Denitrification changes nitrogen into a gaseous form.
Explanation:
CORRECT ANSWER WILL BE MARKED BRAINIEST
predict the chemical formula that results when the following pairs of ions combine to form an ionic bond.
1. K+1 and S-2
2. Pb+4 and N-3
A student graphed the position of a cart during a 7-second time interval.
Which statement best describes the cart?
A.
The cart was stationary except for a short burst of acceleration of 0.5 m/s².
B.
The cart accelerated at a constant rate of approximately 0.8 m/s².
C.
The cart was stationary with a velocity of 0 m/s for the entire 7 seconds.
D.
The cart moved at a constant velocity of 0.5 m/s for the entire 7 seconds.
The cart accelerated at a constant rate of approximately 0.8 m/s². Option (B) is correct.
Option B is the best description based on the graphed position data during the 7-second time interval. The cart's acceleration can be determined by analyzing the shape of the position-time graph.
If the cart was stationary, the position-time graph would be a horizontal line (option C). If the cart moved at a constant velocity, the graph would be a straight line inclined at a constant angle (option D).
However, the graph likely shows a curved line, indicating changing position over time. This suggests that the cart experienced acceleration. To further confirm, calculate the acceleration:
Acceleration (a) = Δv / Δt,
where Δv is the change in velocity and Δt is the change in time.
Given the time interval is 7 seconds, and the initial and final velocities are likely different, you can calculate the average acceleration. If the average acceleration is approximately 0.8 m/s², then option B is correct.
The graphed data aligns with the scenario of constant acceleration, supporting option B.
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Why do we fill balloons
with helium gas instead
of oxygen gas?
Answer:
Helium is less dense. Because helium is lighter than air, a helium balloon rises, just as an air bubble rises in more dense water
Explanation:
Also why not. It just is.
Answer:
This is due to the fact that helium has a lower density. A helium balloon rises like an air bubble in more dense water because helium is lighter than air. Another gas lighter than air is hydrogen, which is even lighter than helium.
Explanation:
What mass of aluminium is needed to react with 640g of iron oxide
Answer:
13.5g
Explanation:
Mole measure the number of elementary entities of a given substance that are present in a given sample. Therefore, 138.8g of aluminium is needed to react with 640g of iron oxide.
What is mole?The SI unit of amount of substance in chemistry is mole. The mole is used to measure the quantity or amount of substance. We know one mole of any element contains 6.022×10²³ atoms which is also called Avogadro number.
Mathematically, the balanced equation can be written as
3Fe[tex]_2[/tex]O[tex]_3[/tex] + 4Al [tex]\rightarrow[/tex] Al[tex]_2[/tex]O[tex]_3[/tex] + 6Fe
number of moles of iron oxide= 640/159.6
=4.01
number of moles of aluminium =(4/3)×4.01
=5.34moles
mass of aluminium =5.34×26
=138.8g
Therefore, 138.8g of aluminium is needed to react with 640g of iron oxide.
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help me please?????
a. Law of conservation of matter
i. What does the law say about matter?
In an AP Chemistry laboratory, students were given two unlabeled beakers and told that one of the beakers contained 1.0g of solid CaCO3 and the other contained
1.0g of solid AgNO3. They were told to devise an experiment to identify which compound was which. A student did so by adding 50 mL of distilled water to each beaker. Describe the student's observations that allowed him to identify each compound.
When the student adds 50 mL of distilled water to each beaker, CaCO3 will not dissolve in water while AgNO3 will dissolve completely in water.
We have to recall that according to the solubility rules, the carbonates of group two elements are insoluble in water. The solubility rules offer a convenient way of predicting the solubility of a compound in water.
When the student adds 50 mL of distilled water to each beaker, CaCO3 will not dissolve in water while AgNO3 will dissolve completely in water. This is because, the carbonates of group two elements are insoluble in water.
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What type of flower structures do you see in a ovary in a flower
Answer:
The ovary contains ovules
Explanation:
Salt dissolving in water is an example of what?
chemical change
chemical property
Physical Change
Answer:
chemical change
Explanation:
because chemical chande is a permanent change
I'm horrible at Chem plse help! Determine whether the reaction given below would be spontaneous or not. JUSTIFY your answer.
Mg2+ (aq) + Ag (s) → Ag+ (aq) + Mg (s)
Thank you
Answer:
This is a not a spontaneous reaction.
Explanation:
No, it would not be one because if you add the reactants the products would have to be the same (same types of atoms. number of atoms, and the arrangement of the atoms). In this case the reactants and the products are not equal.
Study the chemical equation.
Na + Cl2 → NaCl
Is the chemical equation properly balanced?
Step 2: Predict the Number of Nuclei at Each Half-Life
0.5"
Using the values from Step 1, predict the pattern
for the decay of 100 atoms over the course of eight
half-life cycles, Round to the nearest whole
number of atoms. Record in the appropriate
blanks
Time- Half-
Life Cycles, no
Initial
Radioactive Atoms
(Predicted)
100
1
1
0.5
А
2
0.25
A= 27
25
3
0.125
B
B = 16
4.
0.0625
6
C = 9
5
0.03125
С
D=4
6
0.015625
D
7
0.0078125
1
E
8
0.00390625
E
DONE
) Intro
Answer:
A=50
B=13
C=3
D=2
E=0
Explanation:
What is the word equation for Sodium Hypochlorite?
Answer:
Can u phrase differently?
Answer:
If you are looking for the formula, then it is NaOCl
Explanation:
What does percent composition tell you about a molecule?
O A. It tells you the ratio of elements in the molecular formula.
OB. It gives you the total number of atoms in the molecule.
C. It tells you how much of a molecule is made up of each element.
O D. It tells you how the elements are arranged in the molecule.
Answer:
C
Explanation:
I need the circle question to be answered please help me this.
Answer:
(iii):
Reaction 1: Addition
[ We added chlorine to 2-propene ]
Reaction 2: Substitution
[ We substituted hydroxyl ion with chloride ion ]
Reaction 3: Oxidation
[ Acidified permanganate solution is a strong oxidizing agent. So we oxidized propanol to propanoic acid ]
Reaction 4: Acid - base
[ A base (Sodium hydroxide) is added to an acid (propanoic acid) to form a neutral salt ( Sodium propanoate ) ]
What is Art Conservation?
Answer:
The conservation and restoration of cultural property focuses on protection and care of cultural property, including artworks, architecture, archaeology, and museum collections. Conservation activities include preventive conservation, examination, documentation, research, treatment, and education
Explanation:
this is the correct answer
What is phase change? How does matter change in phase?
Answer ASAP pls :(
Answer:
when the chemical composition of a substance change and it is not reversible it is called phase change.for example: turning milk in to yogurt
for each type of geometry in the simulation, examine the resulting bond angles by clicking the show bond angles checkbox. based on your observations for each geometry, provide the bond angles at the indicated locations for the two-dimensional representations of the three-dimensional structures.
The bond angles in PCl5 are 90° and 180° respectively. The bond angle in NH4^+ is 109°.
Bond angles refer to the angle between two atoms bonded to the same central atom. Several factors such as electronegativity difference and presence or absence of lone pairs on the central atom all affect the bond angle.
For NH4^+, the indicated bond angle is 109° and the specie is tetrahedral. For the specie, SF6, the indicated bond angles are 90° and 180° respectively. For HCN, the indicated bond angle is 180°. For PCl5, the indicated bond angles are 90° and 180° respectively.Learn more: https://brainly.com/question/2192784
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this is the text code sir
Answer:
okay?
Explanation:
Answer:
[tex]\huge\blue{\boxed{\tt{\colorbox{black}{babyheaven}}}}[/tex]
The temprature at which a solid melts is the same as the temprature at which its luqid form solidifies.TRUE OR FALSE.PLS GUYS HELP ME!
Answer:
The statement is true
Explanation:
The temperature at which a solid melts is the same as the temperature at which its liquid solidifies
its answer is true cause the temprature of melting ice is same as the liquid solidifies
What’s a conjugative Bas of OH-
Answer:
the answer is O²- hopefully
how many core electrons are there in a sodium atom?
Answer:
There are 13 core electrons in a sodium atom.
With which instrument can you measure the mass of a solid?
You can use Balances and Scales..
Which of the following typically increases the rate of a chemical reaction? А avoiding the use of a catalyst B heating the reaction C increasing the volume of the reaction vessel D decreasing the concentration of the reactants
B: heating the reaction
hope i could help :D
Which of the following are elements? (Select all that apply.)
KCl
Na
C
H2O
Answer:
Na(Sodium) and C(Carbon) only
Answer:
Na, C
Explanation:
1. KCl, or potassium chloride, is a combination of two elements- so it's a chemical compound.
2. Na, or sodium, can be found on the periodic table of elements. Therefore, it is an element.
3. C, or carbon, can also be found on the periodic table of elements. Therefore, it is an element.
4. H20, or water, is a combination of 2 hydrogen atoms that bonded into an oxygen atom. Combination of 2 or more elements is a chemical compound.
Therefore, the answers are Na and C.
2AlCl3 --> 2Al + 3Al2
If you produce 15 moles of Al, how many grams of AlCl3 decomposed?
Answer:
1597,5 gm AlCl3 decomposed
Explanation:
2AlCl3 --> 2Al + 3Al2 If you produce 15 moles of Al, how many grams of AlCl3 decomposed?
FIRST, you need to write down the the correct reaction. Your equation makes no sense
here is the correct question
2AlCl3 --> 2Al + 3Cl2 If you produce 15 moles of Al, how many grams of AlCl3 decomposed?
for every mole of Al produced, we decomposed a mole of AlCl3
so we produced 15 moles of Al, so we decomposed 15 moles of AlCl3
15 moles are 15 X 106.5 = 1597,5 gm AlCl3 decomposed
count the atoms in the following example
Need answer ASAP
Answer:
32 atoms.
Explanation:
4 x 2 = 8 +
4 x 3(O3) = 12 +
4 x 3(SO3) = 12; 32