Answer:
the correct answer is D. Both energy and mass can enter or exit a closed system.
Explanation:
Answer: A.
Explanation:
only energy can enter or exit a closed system
What element is in period 4 and is in group 18
Answer:
Krypton is the element
Symbol: Kr
204,900,000,000
How many significant digits are found?
Answer:
4
Explanation:
There are 4 significant figures because when there is not a decimal, then only numerical values over 0 are counted. So the numbers counted in sig figs are 2049, and none of the other 0s.
So if it was 204,900,000,000.0, then it would have 12 significant figures.
in an oxidation-reduction reaction, how is the reducing agent changed?
Explanation: The additional terminology comes from the definition that, within redox processes, a reductant transfers electrons to an oxidant; hence, the reductant (reducing agent) loses electrons, so is oxidized, while the oxidant (oxidizing agent) gains electrons, so is reduced.
In an oxidation-reduction reaction, the reducing agent loses electrons and loses potential energy, Therefore, option (C) is correct.
What is a reducing agent?A substance that loses its electrons in a redox reaction to other substances and gets oxidized is called a reducing agent. A reducing agent is one of the reactants which reduces the other reactant by donating the electrons to the reactant of an oxidation-reduction reaction.
If the reducing agent can't pass electrons to another reactant in a reaction, then the reduction process does not occur and the reaction cannot proceed.
In redox reactions, when an electron loses potential energy as a result of the transfer and energy is released. Electrons with more potential energy are associated with less electronegative atoms and less potential energy is associated with a more electronegative atom (such as O).
Therefore, the reducing agent loses electrons and loses potential energy in a redox reaction.
Learn more about reducing agent, here:
https://brainly.com/question/15584308
#SPJ2
Your question is incomplete, but probably the complete question was,
In an oxidation-reduction reaction, how is the reducing agent changed?
(A) it gains electrons and gains potential energy
B) it gains electrons and loses potential energy
C) it loses electrons and loses potential energy
D) it loses electrons and gains potential energy
What is the. chemical formular name of rusting?
Answer:
Iron(III) oxide
Explanation:
What type of intermolecular bond may form between na and br
Answer:
Ionic
Explanation:
Na is a metal and Br is a non-metal. Makes an ionic bond. Hope that helps
During chemical reactions__________are broken and___________to form
new substances with different properties, but mass is still_____________ .
Answer:
1st blank : Atoms
2nd blank : Reactants
I'm still trying to find the 3rd blank. I'll put it in comments if I find it
Explanation:
Hope this helps :)
Pls make brainliest :}
And have an amazing day <3
for the sn1 reaction, draw the major organic product, identify the nucleophile, substrate, and leaving group, and determine the rate limiting step.
C4H9OH is the substrate, Br- is the nucleophile and H2O is the leaving group.
In an SN1 reaction, the rate limiting step is the formation of the carbocation. The carbocation is formed as water which is the leaving group departs. After the leaving group departs, the nucleophile (Br-) attacks to yield the major organic product. The protonation of the -OH group is the first step in the reaction.
It then follows that, C4H9OH is the substrate, Br- is the nucleophile and H2O is the leaving group.
Learn more: https://brainly.com/question/22824409
How many grams of Hydrogen (H) would need to react with 143 grams of Oxygen (O) to make 235 grams of Water (H20)? 235
Answer:
45 grams
Explanation:
Someone pls help me I will make you brain
Answer:
Carbon Monoxide- D)
Nitrogen Oxides- A)
Particulate matter- C)
Sulfur Oxides- B)
Explanation:
Answer is 100% verified
Count on me, I'm a Chemistry Guru
NEED HELP ASAP! Write a statement explaining your claim about whether or not the equation is correctly balanced.
Then, provide evidence that supports your claim about whether or not the equation is correctly
balanced. Next, connect your evidence to your claim about the equation.
Answer:
I think that it it correctly balanced that is my opinion and, because the way it is set up, that the answer will tell you weather or not it is correctly balanced or not.
Evaluating the number of atoms of each element on the product and reactant side, we can conclude that the student's equation isn't balanced.
Given the chemical reaction :
[tex] Al_{4}C_{3} + 6H_{2}O ---> 3CH_{4} + 4Al(OH)_{3} [/tex]
For a balanced equation, the number of atoms of each element in the product side must be equal to that on the reactant side.
Number of hydrogen :
Reactant side = (6 × 2) = 12
Product side = (6 × 2) + (6 × 2) = 12 + 24 = 24
Product side ≠ reactant side ; Hence, the equation isn't balanced
The balanced equation for the reaction goes thus :
[tex] Al_{4}C_{3} + 12H_{2}O ---> 3CH_{4} + 4Al(OH)_{3} [/tex]
Reactant side :
Al = 4
H = (12 × 2) = 24
O = 12
C = 3
Product side :
H = (6 × 2) + (6 × 2) = 12 + 24 = 24
Al = 4
O = 4 × 3 = 12
C = 3
Therefore, the student's equation isn't balanced, the balanced version of the equation has been given .
Learn more :https://brainly.com/question/2720947
plz help fast. Which of the following represents a chemical change? (2 points)
1. decomposition of stone due to acid rain
2. iron's attraction to a magnet
3. the pink color of a rose
4. rocks being smoothed by rapid water movement
Answer:
1. Decomposition of stone due to acid rain.
3. The pink color of a rose.
Explanation:
Chemical changes always end up with new products in an equation, or it has always something to do with chemicals. Physical changes on the other hand, do not result in new products and it just changes the physical properties and physical state of matter of the object.
14. The following are a list of the four parts of John Dalton's atomic theory Indicate which of
the parts have been modified and why.
1. All matter is made of tiny, indivisible particles called atoms
2. All atoms of an element are identical and all atoms of different atoms are different
3. Atoms of one element cannot be turned into atoms of another element.
4. All atoms combine with one another in fixed whole number ratios.
Answer:
1
all matter is made of tiny particles called atom
What is the speed of an object that travels 20 meters in 5
Answer:
5 what
Explanation:
not enough information
Examine the models shown above.where is potential energy the greatest
Answer:
A
Explanation:
Because it is the greatest
What is the molecular mass of Br 2?
Answer:
159.808 g/mol
Answer:
159.80 g/mol
Explanation:
79.90×2=159.80g/mol
Water, made of 1 oxygen atom bonded with 2 hydrogen atoms, is what
Answer:
It is a water molecule.
Explanation:
A water molecule consists of two atoms of hydrogen linked by covalent bonds to the same atom of oxygen. Atoms of oxygen are electronegative and attract the shared electrons in their covalent bonds.
Answer:
A water molecule is an example of a molecule created through covalent bonding. Water is made up of one oxygen atom and 2 hydrogen atoms, hence the chemical symbol H2O. A hydrogen atom is made up of 1 proton at its core and 1 electron that revolves around the core in a three-dimensional orbit.
Explanation:
What does the graph show about the rate of temperature change over time?
Answer:
The temperature is the same overtime.
Explanation:
Since the line on the graph is straight the temperature will be constant.
Three fundamental laws of chemical combination
Answer:
the law of multiple proportions, law of definite proportions, and law of conservation of mass.
Explanation:
(Hope this helps can I pls have brainlist (crown)☺️)
Pls help!!! for 100 points, please only answer if your actually going to help ! A kitten has a mass of 1582 g and accelerates at 1.7 m/s^2. What is the net force acting upon the kitten?
Write down all the givens from the problem.
Are all of the units in the form required to use the generic equation? If not, then show your conversion.
Write the generic equation (equation with variables only) for this problem. Do not add any spaces between letters or symbols.
Substitute your numbers into the generic equation. This is where you show your math work, step by step. Solve the problem
Enter the numeric portion (numbers only) of your answer here rounded to the nearest tenth.
Enter the numeric portion (numbers only) of your answer here rounded to the nearest tenth.
Answer:
2689.4
Explanation:
pls help ASSSAPPPP!!!!
Answer:
b or d
Explanation:
Answer:
The answer is B (it's reactivity)
PLEASE HELP!!
What kind of metal is Co?
Alkali Metal
Transition Metal
Alkaline Earth Metal
Answer:
I believe Cobalt is a Transition Metal.
Answer:
answer is transition metal
An element X exists in three forms A, B and C in the ratio 1:2:3. If C has 10 protonsand the number of neutrons in A, B and C are 10, 11 and 12 respectively,Give the following:(i) Representation of form C of the element X(ii) Electronic configuration of form B of the element(iii) Calculate the average atomic mass.
x21 +ANSWER
(i) Ne-22
(ii)1s2s22p6
(iii)21.3
An element X exists in three forms A, B and C in the ratio 1:2:3. If C has 10 protons and the number of neutrons in A, B and C are 10, 11 and 12 respectively,Give the following:(i) Representation of form C of the element X(ii) Electronic configuration of form B of the element(iii) Calculate the average atomic mass.
(i)C has 10 protons and 12 neutrons so a mass of 10 +12 =22
element 10 is Neon (Ne) so this isotope is Ne-22
(ii) they all have the sane atomic number so the same number of electrons
with an electronic structure of 1s2s22p6
(iii) A weighs 20, B weighs 21, C weighs 22
the ratio is 1:2:3
weighted average weight is therefor
(1X20 +2X21 +3X22)/6 =21.3
differentiate between atomic mass and atomic number
Answer:
The major difference between atomic number and mass number is that the atomic number states the number of protons present in an atom whereas, the mass number indicates the total of the number of protons and the number neutrons present in an atom.
Explanation:
Read that From picture and tell me the answer please
Answer:
1g Hydrogen
Explanation:
Getting to the equation:Calcium in water reacts vigorously to give a cloudy white Precipitate (compound) called Calcium hydroxide alongwith the evolution of Hydrogen gas.
[tex] \boxed{ \mathsf{Ca + H_2O \rightarrow Ca(OH)_2 + H_2}}[/tex]
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
Balancing the equation:This reaction is not in it's balanced form! The number of atoms of Hydrogen on the left is 2 while that on the right is 4,I.e.,they're not equal.
Adding a 2 in front of H2O solves the problem by making the number of atoms of each element on both the sides equal.
[tex] \mathsf{Ca +2 H_2O \rightarrow Ca(OH)_2 + H_2}[/tex]
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
Observations:Looking into the equation more carefully, we see:
1 atom of Calcium reacts with 2 molecules of water to give 1 molecule of Calcium Hydroxide alongwith 1 molecule of Hydrogen gas.
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
Gram atomic and molecular massesMass of one atom of Calcium = it's gram atomic mass
= 40 g
Mass of one "molecule" of Hydrogen
= it's Gram molecular mass
= gram mass of one atom × number of atoms in one molecule
= 1 × 2
= 2 g
So,
according to our observation:
One atoms of Calcium gives one molecule of Hydrogen (during the particular reaction)
=> 40g of Calcium gives = 2g of Hydrogen
•°• 1 g of Calcium gives = [tex] \frac{2}{40} [/tex]
= [tex] \frac{1}{20} [/tex] g Hydrogen
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
Answer:We're provided with 20g of Calcium,
=> 20g of Calcium gives = 20 × [tex] \frac{1}{20} [/tex] g H2
= 1 g H2
_______________
Hope this helps!
The nucleus of most atoms is composed of which of the following sub-atomic particles?
A. tightly packed protons.
B. tightly packed neutrons.
C. tightly packed protons and neutrons.
D. loosely connected protons and electrons.
Answer:
C. Tightly packed protons and neutrons
Explanation:
It consists of two sub-atomic particle namely proton and neutron.
This dense nucleus is responsible for most of the mass of atom.
Answer:
C. tightly packed protons and neutrons
Explanation:
The nucleus of an atom is made of protons and neutrons with electrons orbiting the nucleus.
why does a higher concentration make a reaction faster?
Answer:
Explanation: because more is always better
the positon of hydrogen is conversial in mendleevs perodic table give reason
Answer:
the position of hydrogen is controversial in periodic table because hydrogen is the only element with out neutron. it belongs to 1 st group but it is not placed there .
Explanation:
Which of the following statements is correct regarding the speed and velocity of an object? A. An object’s speed is determined by the distance the object traveled and how long it took the object to travel that distance. B. An object’s velocity is determined by the distance the object traveled, how long it took the object to travel that distance and what acceleration the object traveled. C. An object’s velocity is determined by the distance the object traveled and how long it took the object to travel that distance. D. An object’s speed is determined by the distance the object traveled, how long it took the object to travel that distance and what direction the object traveled.
Answer:
Explanation:
D
An object’s speed is determined by the distance the object traveled, how long it took the object to travel that distance, and what direction the object traveled. This statement is correct regarding the speed and velocity of an object.
What is velocity ?The directional speed of an item in motion, as measured by a specific unit of time and viewed from a certain point of reference, is what is referred to as velocity.
Velocity is the pace and direction of an item's movement, whereas speed is the time rate at which an object is travelling along a route.
Constant acceleration and constant velocity are both forms of motion, as you have already read. Because acceleration is the rate at which velocity changes, constant velocity and constant acceleration go hand in hand.
Thus, option D is correct.
To learn more about velocity, follow the link;
https://brainly.com/question/18084516
#SPJ2
Please help me with chem, it would be very appreciated!
why it is necessary to draw a Lewis diagram before predicting the shape of a molecule
To determine the shapes of molecules, we must become acquainted with the Lewis electron dot structure. Although the Lewis theory does not determine the shapes of molecules, it is the first step in predicting shapes of molecules. The Lewis structure helps us identify the bond pairs and the lone pairs.
Please mark BRAINLIEST.
Suppose you've just heard an opera singer warm up her voice. Write your own science question about the sounds a singer makes.