Answer:
b. contains only valence electrons.
Explanation:
In Lewis dot diagram valence electrons are shown by the dots around the symbol of an atom. Consider the example of sodium fluoride.
Electron dot diagram is attached below.
Sodium is alkali metal and present in group one. It has one valence electron. All alkali metal form salt when react with halogens.
Sodium loses its one electron to get stable. While all halogens have seven valence electrons they need only one electron to get stable electronic configuration.
When alkali metals such as sodium react with halogen fluorine it loses its one valence electron which is accepted by fluorine and ionic bond is formed. The compound formed is called sodium fluoride.
Na + F → NaF
PLEASEEE HELP SCIENCE A cold front forms when cold, dense air moves under warm, less dense air, as shown in the
following illustration. Cooler weather usually follows a cold front. Cold fronts often bring other weather
changes.
5. View the image below and answer the question.
Answer:
where is the question?
what is the voltmeter reading this time?
Fill in the blank: An object is most likely to sink in water if
Answer:
An object floats when the weight force on the object is balanced by the upward push of the water on the object. ... If the weight force down is larger than the upward push of the water on the object then the object will sink. If the reverse is true then the object will rise – rising is the opposite of sinking.
Explanation:
Take what you will from this.
Answer:
Wood, rubber, plastic, egg, palm leaves, styrofoam, and some types of natural rocks too!
Arrange K, Li, and Cs in order of increasing atomic size please
Answer:
Li,K,Cs
Explanation:
What do you think the study of chemistry might be about?
Answer:
Think about it. Chemistry is the study of matter.
Explanation:
Anything that has mass and takes up space, and the changes that matter will have when it is in different environments or conditions. Chemistry is used everyday with the development of plastics, wood burning, prescriptions, cosmetics, etc. Everything you touch is made of an element. there's 5 branches of chemistry including Biochemistry, organic chemistry and physical chemistry. -(you find the others).
Chemistry studies our surroundings on a molecular level through atoms and molecules with chemical reactions and understanding the specific properties. There are patterns on the periodic table you should check out.
good luck and have fun!
Answer:
chemistry is the study of structure of substance and what happens to them in different conditions
Which statement best compares pure substances to mixtures?
Pure substances contain small amounts of impurities. Mixtures contain large amounts of
impurities.
Pure substances must be made of two chemical materials. Mixtures can be made of only one
chemical material.
Pure substances are either compounds or elements. Mixtures are homogeneous or
heterogeneous combinations.
Pure substances are liquids dissolved in liquids or gases dissolved in gases. Mixtures are
gases dissolved in liquids or solids dissolved in liquids.
Answer:
pure substances contain small amount of impurities . mixture contain large amounts of impurities
Pure substances are either elements or compounds while mixtures are homogeneous or heterogeneous combinations.
What is Pure substance and mixture?Elements are pure substances as they cannot be broken down into simple substances by any chemical or physical methods as they have only one type of atom in the whole composition.
A pure substance is composed of two or more elements that are chemically combined in a definite proportion. That type of pure substance is called a compound. Water is a pure compound made up of a combination of oxygen and hydrogen.
A mixture is composed of two or more different types of substances which are physically combined. A mixture can separate back into its original components. These types of impure substances are also referred to as mixtures.
A mixture can be either homogeneous or heterogeneous. Cement is a calcium compound solid it is considered a homogeneous mixture while famous gaseous heterogeneous mixes such as cologne and perfume.
Therefore, statement (C) best compares pure substances to mixtures.
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Which chemical formula shows a covalent compound?
NaCl
HBr
MgO
CO2
Answer:
CO2
Explanation:
A covalent compound is a compound between 2 nonmetals. For this reason, NaCl and MgO can be eliminated since both contain metals. While neither H nor Br are metals, in HBr H is acting as a metal. CO2 is the only choice containing both nonmetals, with both elements acting like nonmetals as well.
HELP!!
How is the Earth's interior characterized? and provide a real-world example
Answer:
FREE POINT!!!!!!!!
Explanation:
Similar plant and animal fossils
have been found on continents
that are now separated by an
ocean. Why is this significant?
Identify arrows pointing to structures containing sigma bonds.
Answer:
Identify arrows pointing to bonding electrons.
✔ a, b, d
Identify arrows pointing to nonbonding electrons.
✔ c
Identify arrows pointing to structures containing sigma bonds.
✔ a, b, d
Identify arrows pointing to structures containing pi bonds.
✔ a
Explanation:
Answer:
1) option c 2) c 3) option b 4) a
Explanation:
In a home, what would cause air to cool and sink? and what would make that cooler air actually rise again?
B3F10 what compound name is this?
Answer:
Naming Compounds
Naming Ionic Compounds
An ionic compound is named first by its cation and then by its anion.
LEARNING OBJECTIVES
Convert between the chemical formula of an ionic compound and its name
KEY TAKEAWAYS
Key Points
Most cations and anions can combine to form neutral compounds (typically solids under normal conditions) that are usually referred to as salts.
The net charge of an ionic compound must be zero. Therefore, the number of cations and anions in an ionic compound must be balanced to make an electrically neutral molecule.
When naming ionic compounds, the cation retains the same name as the element. The anion’s name is similar to the elemental name, but the ending of the name has been removed and replaced with “-ide.”
If a metallic element has cations of different charges, which cation is used has to be indicated by its suffix (an older method) or by Roman numerals in parentheses after its name in writing (the Stock system ).
Key Terms
Stock system: A system of naming that includes using Roman numerals to indicate the charge on transition metals.
In chemistry, an ionic compound is a chemical compound in which ions are held together by ionic bonds. Usually, the positively charged portion consists of metal cations and the negatively charged portion is an anion or polyatomic ion. Ionic compounds have high melting and boiling points, and they tend to be hard and brittle.
Ions can be single atoms, as the sodium and chlorine in common table salt (sodium chloride), or more complex (polyatomic) groups such as the carbonate in calcium carbonate. But to be considered an ion, they must carry a positive or negative charge. Thus, in an ionic bond, one ‘bonder’ must have a positive charge and the other a negative one. By sticking to each other, they resolve, or partially resolve, their separate charge imbalances. Positive to positive and negative to negative ionic bonds do not occur.
Most cations and anions can combine to form solid compounds that are usually known as salts. The one overriding requirement is that the resulting compound must be electrically neutral: therefore the ions Ca2+ and Br– combine only in a 1:2 ratio to form calcium bromide, CaBr2. Because no other simpler formula is possible, there is no need to name it “calcium dibromide.” CaBr2 can be named using either the Stock method or the older, classic way of naming.
For example, CuCl2 indicates a molecule where one Cu2+ cation associates with two Cl– anions to form a neutral compound. Its systematic name is copper (II) chloride, where copper’s oxidation number is indicated in parentheses. Its older name is cupric chloride.
The Stock Method of Naming
An ionic compound is named first by its cation and then by its anion. The cation has the same name as its element. For example, K+1 is called the potassium ion, just as K is called the potassium atom. The anion is named by taking the elemental name, removing the ending, and adding “-ide.” For example, F-1 is called fluoride, for the elemental name, fluorine. The “-ine” was removed and replaced with “-ide.” To name a compound, the cation name and the anion named are added together. For example, NaF is also known as sodium fluoride.
If either the cation or the anion was a polyatomic ion, the polyatomic ion name is used in the name of the overall compound. The polyatomic ion name stays the same. For example, Ca(NO3)2 is called calcium nitrate.
For cations that take on multiple charges (typically transition metals), the charge is written using Roman numerals in parentheses immediately following the element name. For example, Cu(NO3)2 is copper (II) nitrate, because the charge of two nitrate ions (NO3−1) is 2(-1) = -2. Since the net charge of the ionic compound must be zero, the Cu ion has a 2+ charge. This compound is therefore, copper (II) nitrate. The Roman numerals in fact show the oxidation number, but in simple ionic compounds this will always be the same as the metal’s ionic charge.
The Old, Classic, or Common Way of Naming
image
Names of some ionic compounds: Common, or trivial, names of compounds are sometimes used in informal conversations between chemists, especially older chemists. Systematic names are formal names that are always used in print.
Since some metallic elements form cations that have different positive charges, the names of ionic compounds derived from these elements must contain some indication of the cation charge. The older method uses the suffixes -ous and -ic to denote the lower and higher charges, respectively. In the cases of iron and copper, the Latin names of the elements are used (ferrous/ferric, cuprous/cupric). This system is still used, although it has been officially supplanted by the more precise, if slightly cumbersome, Stock system. In both systems, the name of the anion ends in -ide.
Explanation:
What can light and other electromagnetic waves do to objects.
Answer:
It can cause a reflection
Explanation:
Reflection is when incident light (incoming light) hits an object and bounces off. Very smooth surfaces such as mirrors reflect almost all incident light
How many liters are in 17.5 g of potassium sulfate?
Answer:
66.24 liters
Explanation:
Find the three missing terms pound in this puzzle.
e t d w a t
s p l t I h
n u o e r I
e h c y m n
d n a p x e
What does the identity of an element depend on the number of?
A. protons in the atom
B. electrons in the atom
C. protons and neutrons in the nucleus
D. neutrons in the atom
Answer: A. protons in the atom
Explanation: I just took the test and got a 100% so this should be right. Unless the question is worded differently than mine then it should be right. Hope this helps :)
Answer:
A
Explanation:
Chemistry:
A sample of helium occupies 1820 mL at 719 mmHg. Assume that the temperature is held constant and determine (a) the volume of the helium at 752 mmHg and (b) the pressure, in mmHg, if the volume is changed to 345 mL
Answer:
You can use the Boyles Law formula
P1V1 = P2V2
Substitute what you have and solve for the new volume. There is no need to do any conversions:
730mmHg * V1 = 719mmHg* 1820mL
V1 = 719mmHg* 1820mL / 730mmHg
V1 = 1792mmHg
The correct answer should have only 2 significant figures: Volume = 1800mL
Explanation:
hope that this helps
The volume of the helium at 752 mmHg is 1740 ml and the pressure, in mmHg, if the volume is changed to 345 mL is 3792 mmHg.
What is pressure?Pressure is defined as the force applied perpendicular to an object's surface per unit area over which that force is dispersed.
It is also defined as the physical force exerted on an object.
(a) The volume of the helium at 752 mmHg
P1V1 = P2V2
719 mmHg x 1820 ml = 752 mmHg x V2
V2 = 719 mmHg x 1820 ml / 752 mmHg
V2 = 1740 ml
(b) The pressure, in mmHg, if the volume is changed to 345 mL
719 mmHg x 1820 ml = P2 x 345 ml
P2 = 719 mmHg x 1820 ml / 345 ml
P2 = 3792 mmHg
Thus, the volume of the helium at 752 mmHg is 1740 ml and the pressure, in mmHg, if the volume is changed to 345 mL is 3792 mmHg.
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If you were to use 3.50 mL of 0.250 M copper(II) sulfate in an experiment similar to the one you just
completed, what volume of 0.250 M sodium hydroxide would you need so that neither was a limiting
reactant? Justify your answer.
A tube containing 8.00 mL of 0.250 M copper(II) sulfate (CuSOs) contains 2.00 x 10 mole of
coppen II) sulfate. How many grams of solid copper(II) sulfate would this be equivalent to? Show
your work using dimensional analysis.
6.
How many moles of sodium hydroxide would be needed for a complete reaction with 4.80 x 10- mole
-
11
Answer:
a. volume of NaOH needed = 0.07 L or 7.0 mL since mole ratio of CuSO₄ to NaOH is 1 : 2
b. mass of copper (ii) sulfate = 0.32 g
c. Number of moles of NaOH needed, Y = 9.6 * 10⁻¹¹ moles of NaOH
Explanation:
The equation of the reaction is as follows:
CuSO₄ (aq) + 2NaOH(aq) —> Na₂SO₄ (aq) + Cu(OH)₂(s)
Number of moles of CuSO₄ in 3.50 mL of 0.250 M solution
number of moles = molarity * volume
number of moles = 0.250 M * 3.50 mL * 1L/1000 mL = 0.000875 moles
since mole ratio of CuSO₄ to NaOH is 1 : 2,
number of moles of NaOH required = 2 * 0.000875 = 0.00175moles
volume of NaOH required = number of moles/molarity
volume = 0.00175/0.250
volume = 0.07 L or 7.0 mL
b. number of moles = molarity * volume
number of moles = mass/molar mass
molar mass of CuSO₄ = 160 g/mol
number of moles = 0.250 mol/L * 8.00 mL * 1 L/1000 mL
number of moles = 2.00 * 10⁻² moles
2.00 * 10⁻² moles = mass/160 g/mol
mass = 2.00 * 10⁻² moles * 160 g/mol
mass = 0.32 g
c. Mole ratio of CuSO₄ to NaOH is 1 : 2
let number of moles of NaOH be Y
1 mole of CuSO₄/2 moles of NaOH= 4.8 * 10⁻¹¹ moles of CuSO₄/ Y
Y = 2 moles of NaOH * 4.8 * 10⁻¹¹ moles of / 1 moles of CuSO₄
Y = 9.6 * 10⁻¹¹ moles of NaOH
A gas is at 45L at 227K. What volume would the gas be at 311K?
Answer:
sorry I don't know the ans.. I'm truly sorry
Bobby claimed that because bubbles are formed when boiling water it must be a chemical change. He argued that a gas is being created, which is a sign of a chemical change. Evan disagreed, saying that that it did not change into a different substance and was thus a physical change. Who do you agree with? Explain your reasoning
Answer:
I disagree with Evan's explanation for chemical change with regards to formation of bubbles.
Explanation:
Chemical change usually affects the chemical composition, whereas physical change only affects the appearance of the substance and is easily reversible.
The bubbling water is just going through change of phase, but its overall chemical composition isn't altered, Hence, it is a physical change, and not chemical.
I hope this was easy to understand.
What cell has a membrane and ribosomes
Nitrogen boils at -195°C, because it is normally a gas at room temperature. At -250°C, it is a: solid, liquid, gas
Answer:
i think its liquid because they is liquid nitrogen and the gas but i think its liquid
how many moles are in 28.65 grams
Answer:
There are 0.24952533574875027 moles for 28.65 grams.
Explanation:
1 gram = 0.0087094358027487 mole
A method that uses a mathematical equation and the half-life of decay to determine the exact date of a fossil is known as _______. A. Relative dating c. Absolute dating b. Comparative dating d. Half-life dating Please select the best answer from the choices provided A B C D
Answer:
c. Absolute dating
Explanation:
Absolute dating is a mathematical process that is still used today by traditional archaeology to determine the chronological age of a given discovery. This type of dating provides an era or time interval expressed in numbers. This system would therefore be in contrast with relative dating, which positions the events concerning a known reference but without ascertaining the annual difference between the elements taken into consideration.
When we talk about absolute dating we are talking about four different systems:
Radiometric dating, which in turn is divided between carbon-14 and potassium-argon.The luminescence, divided into “Thermoluminescence” e “OSL”.Dendrochronology and;Dating with amino acids.Answer:
c
Explanation:
What advice should you give to a person exercising on a very hot day?
O A. Remember to wear lots of clothes so you can sweat off more weight!
O B. Take a lot of breaks, and remember to drink fluids!
O C. Don't drink anything, it will give you cramps.
O D. Go all out! A hot day is the best time to try for a personal best.
Answer:
B
Explanation:
You should drink lots of water and take breaks.
Answer:
B
Explanation:
Just answered it in gizmos
What’s the biggest molecule
Answer:
PG5
Explanation:
Hope this helps and have a great day!
Which of the following statements concerning the
melting of ice, which occurs in segment BC, is true?
rections: Use the graph below to answer any questions
t follow
OA. The particle motion decreases.
Heating/Cooling Curve for Water
o
B. The particle motion is unaffected.
o
C. The temperature increases throughout the
phase chang
D
E
100-
Temperature
O D. The temperature stays the same until all the
ice has melted.
B
00+
C
А
Energy Added as Heat
Answer you need an right amout of fecal matter
h
Explanation:f ///////////////////////////////////////////c/v
Answer:
D
Explanation:
tpt Cell theory has three parts: The cell is the basic unit of life in all living things, all cells come from existing cells, and
Answer:
All cells come from cells.
Explanation:
Basically meaning that the cells just infinitely reproduce themselves.
Which term describes the dashed line shown in the graph
Answer:
Where's the graph?
Explanation: