Answer:
A burning match represents an exothermic reaction. The chemicals release energy in the form of heat and light as the reaction progresses.
Explanation:
Sample Response
Why are atoms neutral?
A They have neutrons in the nucleus
B. They have the same number of protons and electrons
They tend to have 8 valence electrons
D
None of the above
Answer:
B. They have the same number of protons and electrons
Explanation:
Protons have a charge of +1, electrons have a charge of -1, and neutrons have no charge, making them neutral. When there are the same number of protons as there are electrons, the charges balance out, leaving you with a neutral atom.
How many electrons does each lithium atom provide to the voltaic cell?
A. 1
B. 2
C. 3
D. 4
Answer:
c. 3 electrons
Explanation: for the element of LITHIUM, you already know that the atomic number tells you the number of electrons. That means there are 3 electrons in a lithium atom.
A 55kg skier accelerated at 3 m/s^2. How much force must the skier exert?
Answer:
The answer is 165 NExplanation:
The force acting on an object given it's mass and acceleration can be found by using the formula
force = mass × accelerationFrom the question
mass = 55 kg
acceleration = 3 m/s²
We have
force = 55 × 3
We have the final answer as
165 NHope this helps you
How do you figure out what roman numeral to use? Give a specific example
Answer:Explanation:
The Roman numeral must have the same value as the charge of the ion. In our example, the transition metal ion Fe2+ would have the name iron(II). Add the name of the anion to the transition metal ion. In our example, FeCl2 would have the name iron(II) chloride since the anion is Cl-, which has the name chloride.
Is it reasonable to expect that the atom model will change again in time?
I need some good help
Answer:
lol
Explanation:
Answer:
felt that.__________
How many d electrons does I (atomic number
53) possess?
1. 10
2. 5
3. 8
4. 0
5. 20
6. 53
7. 16
Answer:
6. 53 is the answer. Hope this helps:)
The number of d electrons that an atom of atomic number 53 possess are 20. Thus, the correct option for this question is 5.
What is an Atomic number?An atomic number may be defined as the number of protons in the nucleus of an atom that significantly represents the characteristic of a chemical element and determines its specific place in the modern periodic table.
According to the modern periodic table, an element that has an atomic number of 53 is known as Iodine. Its electronic configuration is [tex]1s^2, 2s^2, 2p^6, 3s^2, 3p^6, 4s^2, 3d^1^0, 4p^6, 5s^2, 4d^1^0, 5p^5[/tex]. Thus, according to this electronic configuration, the total number of d electrons are [tex]3d^1^0 and 4d^1^0[/tex].
Therefore, the number of d electrons that an atom of atomic number 53 possess are 20. Thus, the correct option for this question is 5.
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Temperature is a measure of the average _____energy of particles in a substance.
Answer:
kinetic energy
Explanation:
Answer:
kinetic energy
Explanation:
In physics, the kinetic energy of an object is the energy that it possesses due to its motion. It is defined as the work needed to accelerate a body of a given mass from rest to its stated velocity. Having gained this energy during its acceleration, the body maintains this kinetic energy unless its speed changes.
Why are prefixes used in naming covalent compounds?
Answer:
1 - mono
2 - di
3 - tri
4 - tetra
5 - penta
6 - hexa
7 - hepta
8 - octa
9 - nona
10 - deca
Explanation:
These are prefixes that can go on an element.
For example:
CO2= Carbon Dioxide
Answer:
The same atoms can combine in more than one ratio.
Explanation:
With radiocarbon dating, scientists compare an object's carbon-14 levels with _____. the carbon-14 levels of an object from the same time period carbon-14 levels in the atmosphere the carbon-14 levels in the rock surrounding the object the object's carbon-12 levels
Answer:carbon-14 levels in the atmosphere
Explanation:
When carrying out radiocarbon dating, the level of carbon-14 in a sample is compared with the level of carbon 14 in the atmosphere because, objects exchange carbon-14 with the atmosphere.
Comparison of the activities of carbon-14 in the atmosphere and in the sample gives the age of the sample since the half-life of carbon-14 is a constant.
What is the chemical name for Cu(NO3)2
Answer:
The chemical name is Copper(II) nitrate
Explanation:
HURRY !The number of electrons in an atom decreases as you move from left to right in the periodic table.
Please select the best answer from the choices provided
T or F
I believe this is false, due to the fact that atomic radius decreases while you move right to left...but please, correct me if I'm wrong ^^'''
Answer:
False
Explanation:
1pt The picture shows the moving molecules in a beaker containing a liquid. What will happen if the molecules increase their speed? A. The liquid will change into a solid. B. The temperature of the liquid will rise. C. The temperature of the liquid will fall. D. The molecules wil gain mass. her is the picture
Answer:
B. The temperature of the liquid will rise.
Explanation:
As the molecules present in the beaker will increase their speed that will result in rise in the temperature of the liquid.
This is so because as the movement or motion of molecules increases, atoms vibrate faster, and its collision with each other and with the wall of the beaker increases that causes a rise in the temperature of the liquid. If the molecules move slowly then the temperature will fall down.
Hence, the correct answer is "B. The temperature of the liquid will rise.".
why does it take more energy to evaporate water than to melt ice?
Answer:
The energy required to completely separate the molecules, moving from liquid to gas, is much greater that if you were just to reduce their separation, solid to liquid. Hence the reason why the latent heat of vaporization is greater that the latent heat of fusion.
Answer:
It takes longer to boil water than to melt ice because of the difference in the amount of heat required to overcome the forces of attraction by keeping the temperature constant during this time. ... This is the reason it takes longer in boiling than in melting.
Select the correct answer
Which statement best supports the idea that water conservation is important for human societies?
OA Once humans use water, it cannot be reused ever again,
OB. Only about 1% of the freshwater on Earth is easily accessible.
OC Water is constantly being lost from the hydrosphere
OD. Most land animals use salt water instead of freshwater.
Answer:
Only about 1% of the freshwater on Earth is easily accessible.
Explanation:
Freshwater accounts for a minimal proportion of water resources on planet earth. About 70 percent of the world surface area is covered by water, but only about 2.5 percent of this mass of water is fresh. The remaining are marine or salt water. Amazingly, just about 1 percent of this freshwater is easily accessible. The other 1.5% is trapped in glaciers and snowfields.
This underscore the need for water conservation on the planet since fresh water is a scarce resource and people living in many areas have no access to fresh water.
What is the relationship between variable x and variable y?
As variable x increases, variable y increases.
As variable x increases, variable y decreases.
Both variables show a trend toward decreasing values.
No distinct relationship exists between variables x and y.
Answer:
So x is usually called the independent or explanatory variable, and y the dependent or response variable. Another way to think about it, sometimes, is that x is used to predict y. So x is something that comes before y in time. That is why, for example, height at age 2 is on the x axis and height at age 18 on the y
Explanation:
hope this helpss
x is independant and y in dependant .
which balances the equation Mg + O2 → MgO
Answer:
2Mg+[tex]O_{2}[/tex]→2MgO
Explanation:
The first step is magnesium + oxygen equals magnesium oxide
The second step is changing that into an equation which looks like Mg+[tex]O_{2}[/tex]→MgO
The third step is to 2*Mg and 2*O as well as the product has to be 2*Mg,2*O which gets the equation to become balanced as 2Mg+[tex]O_{2}[/tex]→2MgO
The coefficient 2 balance the given reaction. The balanced equation for the given reaction is given as [tex]\rm Mg + O_2 \rightarrow 2MgO[/tex].
A balanced equation is a mathematical representation of a chemical reaction that respects the law of mass conservation. It depicts the reactants and products of the reaction, as well as the relative amounts of each species. The unbalanced equation is [tex]\rm Mg + O_2 \rightarrow MgO[/tex]. One magnesium (Mg) atom on the left side and one on the right side, so the magnesium is already balanced. Balance the oxygen (O) atoms. On the left side, there are two oxygen (O) atoms present in the O2 molecule. On the right side, there is only one oxygen (O) atom in the MgO molecule. To balance the oxygen atoms, we need to add a coefficient of 2 in front of MgO: [tex]\rm Mg + O_2 \rightarrow 2MgO[/tex]. The balanced equation is [tex]\rm Mg + O_2 \rightarrow 2MgO[/tex].
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• True False estion 2 (1 point) Water and ice are made from the same molecule H2O True False
Answer:
true i think
Explanation:
pls help ill mark you as brainliest
Answer:
Explanation:
Synthesis- D
Combustion- C
Decomposition- A
Single Displacement- C
Double Displacement- B
the product of 173.06 times 0.21 should be reported as what using proper number of sig figs?
Answer:
36.3
Explanation:
The full answer would be 36.3426, but because of the 0.21, you round it down to 3 sig figs.
name the gas evolved when metal carbonates react with acid and state the method
Answer:
the gas evolved is carbon dioxide
Explanation:
for example we can have a look at sodium carbonate reaction with hydrochloric acid
when sodium carbonate reacts with hydrochloric acid, it results in sodium chloride, carbon dioxide and water.
Answer: Carbon dioxide
If you weighed 25 grams of NaOH in this lab, how many moles of NaOH
would you have?
Magnetic substance is used to seperate
none magnetic substances.
False
True
Answer:
the answer should be true
hope this helps :)
Explanation:
The chemical combination of two or more different atoms in fixed amounts is called a(n)
A. element
B. mixture.
C. orbit
D. compound.
Answer:
D. compound
Explanation:
Answer:
compound
Explanation:
study island
Help me answer the question please I don’t get it this is earth science not chemistry.
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Ionic compounds tend to be ...
A. Hard
B. Soft
C. Bendable
Answer:
A
Explanation:
Answer:
A. Hard
Explanation: got it correct on Edg
Record the length of the object shown.
Answer: 7.26 mm
I did the test already.
how do i know if they are congruent
40 g of CaCO3 is how many moles of CaCO3?
10 moles
0.4 moles
40 moles
100 moles
Answer:
0.4 moles
Explanation:
To convert between moles and grams you need the molar mass of the compound. The molar mass of of CaCO3 is 100.09g/mol. You use that as the unit converter.
40gCaCO3* 1mol CaCO3/100.09gCaCO3 = 0.399640 mol CaCO3
This rounds to 0.4 moles CaCO3
12. A malleable sheet of metal used to wrap food in the kitchen is made of only aluminum. What can be said about the metal sheet?
Answer:
is aluminium prepared in thin metal leaves with a thickness less than 0.2 mm (7.9 mils); thinner gauges down to 6 micrometres (0.24 mils) are also commonly used.[1] In the United States, foils are commonly measured in thousandths of an inch or mils. Standard household foil is typically 0.016 mm (0.63 mils) thick, and heavy duty household foil is typically 0.024 mm (0.94 mils). The foil is pliable, and can be readily bent or wrapped around objects. Thin foils are fragile and are sometimes laminated with other materials such as plastics or paper to make them stronger and more useful. Aluminium foil supplanted tin foil in the mid 20th century.