Answer:
on https://www.ck12.org/book/peoples-physics-concepts/section/20.1/
Explanation:
it shows for calcium 45 and maybe a possible equation on 3/4th's scroll down?
Which causes genetic variations and can result in different alleles
Which of the following is not a part of every scientific investigation?
Group of answer choices
Collection of relevant empirical evidence
Using models to understand objects and processes better
Use of logical reasoning
Devising hypothesis, making predictions
Answer:
the correct answer is Group of answer choices
Using models to understand objects and processes better is not part of every scientific investigation while collection of relevant empirical evidence,use of logical reasoning and devising hypothesis, making predictions is a part.
What is hypothesis?Hypothesis can be defined as an assumption which is made for the sake of argument . It is an interpretation of a practical condition for which action needs to be taken.It is defined as a tentative assumption which is made to test logical consequences.It is an antecedent clause of a statement which is conditional.
It is constructed before research. There are six types of hypothesis 1)simple hypothesis 2) complex hypothesis 3) directional hypothesis 4)non-directional hypothesis 5) null hypothesis 6)casual hypothesis
The hypothesis should be clear and precise, it must be specific and way of explanation of hypothesis should be simple.
Learn more about hypothesis,here:
https://brainly.com/question/29519577
#SPJ2
The skin has and needs natural oils. Why is it advisable
to wear gloves while working with strong alkalis ?
Answer:
As we know that alkalis react with oil to form soap. As our skin contains oil so when we touch strong alkalis, a reaction takes place and the soapy solution is formed. Hence we should wear gloves.
Answer:
As we know that alkalis react with oil to form soap. As our skin contains oil so when we touch strong alkalis, a reaction takes place and the soapy solution is formed. Hence we should wear gloves.
Explanation:
it from internet
What is the two major types of chemical bonding?
Answer:
Ionic bond and covalent bond
Explanation:
The two main types of chemical bonding are ionic bond and covalent bond.
In an ionic bond, there is a transfer of electrons from one atom to another. Usually from a metal to a nonmetal leading to the existence of an ion pair. Ionic compounds are soluble in water and have high melting and boiling points due to the strong electrostatic interaction between ions in the compound.
A covalent bond involves sharing of electrons between atoms. In an ordinary covalent bond, the shared electrons are furnished by the two bonding atoms while in a dative covalent bond, the two bonding electrons are furnished by only one of the bonding species.
Which properties make a metal a good material to use for electrical wires?
Answer: it has 2 characteristics and they are conductivity and ductility
Explanation:
The conductivity makes them great conductors of electricity
Answer:
It's B guaranteed;)
Conductivity and ductility
The table shows the specific heat of four substances—brick, dry soil, paper, and water. If all four substances were exposed to sunlight for the same amount of time, which substance would heat up the fastest?
Answer:
Brick
Explanation:
.................
the name of the compound made from lithium chloride and oxygen
Answer:
Lithium perchlorate
Explanation:
The compound formed from lithium chloride and oxygen is lithium oxide (Li₂O).
When lithium chloride (LiCl) reacts with oxygen (O₂), they combine to form lithium oxide (Li₂O). In this reaction, each lithium-ion (Li⁺) from lithium chloride combines with an oxygen atom (O) from oxygen gas to form a lithium oxide molecule.
The chemical formula Li₂O indicates that two lithium ions are combined with one oxygen atom in the compound. This is because lithium has a +1 charge, and since there are two lithium ions, their combined charge is +2. Oxygen, on the other hand, has a -2 charge, so one oxygen atom is sufficient to balance the charges and form a neutral compound.
Hence, the name of the compound formed is Li₂O
Learn more about compounds here:
https://brainly.com/question/14117795
#SPJ 2
According to the Law of Conservation of Mass, the total
moles of reactants in a balanced chemical equation is...?
O always equal to the total moles of the products.
sometimes more or sometimes less than the total moles of the products.
O always more than the total moles of the products.
O always less than the total moles of the products.
Answer:
Always equal to the total moles of the products.
Explanation:
The law of conservation of mass states that mass in an isolated system is neither created nor destroyed by chemical reactions or physical transformations. According to the law of conservation of mass, the mass of the products in a chemical reaction equal to the mass of the reactants.
any of ya'll good at chemistry?????
Answer:
i good at chemistry
Explanation:
not all but i try
Which diagram shows a pair of electrons that have opposite spins?
O1
1
个个
Answer:
the answer is half arrow
Calculate the volume of an
object with the following
dimension:
4.0 cm x 1.2 cm x 2.5 cm
[?] cm3
Answer: The volume of given object is 12.0 [tex]cm^{3}[/tex].
Explanation:
Given: Length = 4.0 cm
Width = 1.2 cm
Height = 2.5 cm
Formula to calculate the volume of such an object is as follows.
[tex]Volume = length \times width \times height[/tex]
Substitute the values into above formula as follows.
[tex]Volume = length \times width \times height\\= 4.0 cm \times 1.2 cm \times 2.5 cm\\= 12.0 cm^{3}[/tex]
Thus, we can conclude that the volume of given object is 12.0 [tex]cm^{3}[/tex].
Using the periodic table, choose the more reactive nonmetal.
Br or As
Reactivity of non-metals depend on their ability to gain electrons. So, smaller is the size of a non-metal more readily it will attract electrons because then nucleus will be more closer to valence shell. ... Hence, Br is the non-metal which will be more reactive than At.
Answer:
br is more reactive than as
what's the meaning of pH in acids and base
Answer:
pH is a measure of how acidic/basic water is. The range goes from 0 to 14, with 7 being neutral. pHs of less than 7 indicate acidity, whereas a pH of greater than 7 indicates a base. pH is really a measure of the relative amount of free hydrogen and hydroxyl ions in the water.
Question 2
5 pts
_AI(NO3)3 +
K2CO3 →
Al2(CO3)3 +
KNO3
What is the correct set of coefficients used to balance the equation above?
O 2, 3, 1,6
O 2, 6, 1, 3
O 2, 3, 1,9
O 3, 3, 1.2
Answer:
2Al(NO3)3+3K2CO3->Al2(CO3)3+6KNO3
So the right answer is 2,3,1,6
Explanation:
First you look at the equation that isn't balance, you can see Al(NO3)3 while Al2(CO3)3, so you put 2 in Al(NO3)3.
Now we have 2Al is correct, but 6NO3. So we have 6KNO3, it also means we have 6K
Finally, we only have 2K as K2CO3 so we put 3 in it, so we have 3K2CO3.
Sorry about my explanation, it's hard to understand but the answer is correct.
(04.03 MC)
The table shows the nature of the reactants and products formed in a certain type of chemical reaction.
Nature of Reactants and Products
Reactants
lonic compound + lonic compound
Products
lonic compound + lonic compound
Which of the following is true about this type of chemical reaction?
It is a single replacement reaction, and all four compounds are different.
It is a double replacement reaction, and all four compounds are different.
It is a single replacement reaction, and each compound has the same set of ions.
It is a double replacement reaction, and each compound has the same set of ions.
Answer: The given type of chemical reaction is a double replacement reaction, and each compound has the same set of ions.
Explanation:
When two different compounds chemically react with each other and their ions get exchanged with each other then it leads to the formation of two new compounds. This type of reaction is called double displacement reaction.
For example, [tex]KBr + AgNO_{3} \rightarrow KNO_{3} + AgBr(\downarrow)[/tex]
Here, both KBr and [tex]AgNO_{3}[/tex] are ionic compounds that leads to the formation of two new ionic compounds which are [tex]KNO_{3}[/tex] and AgBr.
Thus, we can conclude that the given type of chemical reaction is a double replacement reaction, and each compound has the same set of ions.
If I have 0.294L of a 2.OM NaOH solution, what will be the concentration if I add 1.824L to the solution?
Answer:
0.32M
Explanation:
Using the following formula;
CaVa = CbVb
Where;
Ca = concentration of acid (M)
Cb = concentration of bass (M)
Va = volume of acid (HCl)
Vb = volume of base (NaOH)
According to this question, the following were given:
Ca = ?
Cb = 2M
Va = 1.824L
Vb = 0.294L
Using CaVa = CbVb
Ca × 1.824 = 0.294 × 2
1.824Ca = 0.588
Ca = 0.588 ÷ 1.824
Ca = 0.32M
In a solution containing 21.2 g sodium carbonate in 1.50 L of solution, calculate
the concentration of the sodium and carbonate ions.
Answer:
0.13 molL-1
Explanation:
We must first obtain the number of moles of sodium carbonate as follows;
Number of moles = mass/molar mass
Number of moles = 21.2 g/106 g/mol
Number of moles= 0.2 moles
Number of moles = concentration × volume
Volume = 1.50 L
Concentration = number of moles/volume
Concentration = 0.2 moles/1.5 L
Concentration = 0.13 molL-1
Calculate the molarity of the following solution: 1.0 mole of KCl in .75 L of solution.
1.3 M
2.0 M
0.750 M
99 M
Answer:
1.3 M
Explanation:
1 mole= Concentration * Volume
1 mole=C*0.75 L
C=1.3 M
Can someone please help me!!
Explanation:
Corrections
- It should be 45 bromine atoms
- Bromine isn't found abundantly as atoms, rather as diatomic molecules
[tex]Br_2[/tex]
Before should show 2 phosphorus atom and 3 bromine molecules to form 2 phosphorus tribromide
The bond is covalent because both bromine and phosphorus is a non-metal
A block is pulled 0.90 m to the right in 2.4 s. What is the block's average speed to the nearest hundredths of a m/s?
What benefits and drawbacks do you see with maintaining and preserving nature through national parks?
Where can we find what the chemical symbols in a compound mean? Example: 0, C, Na, Li
Answer:
The periodic table
Explanation:
I'm not really sure what your question is. . . I'm assuming this is what you're looking for
Draw the structural formula (not the skeletal formula) for 2-octene.
Answer:
Explanation:
2-octene is a structural isomer of octene. Octene is an unsaturated hydrocarbon (alkene) with 8 carbon atoms. The structural formula of 2-octene is seen below
H H H H H H
I I I I I I
H- C - C = C - C - C - C - C - C - H
I I I I I I I I
H H H H H H H H
The structural formula of 2-octene is different from that of octene in the sense that, it's double bond is found in between the second and the third carbon (on the second bond position).
Please help .. I’m really stuck
Answer:
See explanation
Explanation:
pOH = -log[OH^-]
pOH =-log[1×10^-4 molL-1]
pOH = 4
pH +pOH =14
pH = 14 -4
pH =11
b) pOH = -log[OH^-]
pOH =-log[4.9×10^-2molL-1]
pOH = 1.31
pH +pOH =14
pH = 14 -1.31
pH =12.69
c)
pH= -log[H^+]
[H^+] = Antilog [-pH]
[H^+] = Antilog [-3]
[H^+] = 1 × 10^-3 molL-1
d) pOH = -log[OH^-]
[OH^-] = Antilog[-pOH]
[OH^-] = Antilog[-10.4]
[OH^-] = 3.98 ×10^-11
[OH^-] [H^+] = 1 × 10^-14
[H^+] = 1 × 10^-14/3.98 ×10^-11
[H^+] =2.5 ×10^-4 MolL^-1
e) A solution of pH 9 is basic because the pH scale is calibrated in such as way that 0-6.9 is acidic, 7 is neutral and 8 - 14 is basic.
f)
[H^+] = number of moles/volume
[H^+] = 0.35 moles/8L
[H^+] = 0.044 MolL^-1
pH = - log [H^+]
pH = -log [0.044 MolL^-1]
pH= 1.36
Under what conditions is AG for a reaction always positive?
whats the net ionic and total ionic equations? include the ions and states pls:
NiCl2 + Na2CO3 = 2NaCl + NiCO3
Answer:
Total ionic equation = Ni²⁺ + 2Cl⁻¹ + 2Na⁺ + CO₃⁻² → 2Na⁺ + 2Cl⁻¹ + NiCO₃ (s)
Net ionic equation = Ni²⁺ + CO₃⁻² → NiCO₃ (s)
NiCl₂ (aq) + Na₂CO₃ (aq) → 2NaCl (aq) + NiCO₃ (s)
First, we'll need to expand the complete chemical equation into a total ionic equation (to determine whether a chemical is aqueous or solid, use a solubility chart until the rules are memorized).
Ni²⁺ + 2Cl⁻¹ + 2Na⁺ + CO₃⁻² → 2Na⁺ + 2Cl⁻¹ + NiCO₃ (s)
Now, using the total ionic equation, we can find the net ionic equation. In order to do this, we need to cancel out the aqueous solutions that don't form into solids, as they are extraneous.
Ni²⁺ + 2Cl⁻¹ + 2Na⁺ + CO₃⁻² → 2Na⁺ + 2Cl⁻¹ + NiCO₃ (s)
Ni²⁺ + CO₃⁻² → NiCO₃ (s)
I hope this helped!
What is the mass in grams of 3.45 moles of N?
mass of 1 mole of N is 14g
so mass of 3.45 mole is
3.45 × 14 = 48.3 g
Which of the following combinations of compounds will make a buffer when
mixed?
A. HCl and NaOH
B. CH3COOH and NaCH3Coo
C.HCl and NaBr
D. CH3COOH and NHACI
Answer:
B. CH3COOH and NaCH3COO
Explanation:
CH3COOH and NaCH3COO will make a buffer when mixed.
What is a buffer solution?Buffer solutions resist a change in pH when small amounts of a strong acid or a strong base are added. A solution of acetic acid and sodium acetate CH3COOH + CH3COONa is an example of a buffer that consists of a weak acid and its salt.
What are buffer solutions and their types?Buffers are broadly divided into two types – acidic and alkaline buffer solutions. Acidic buffers are solutions that have a pH below 7 and contain a weak acid and one of its salts. For example, a mixture of acetic acid and sodium acetate acts as a buffer solution with a pH of about 4.75.
Learn more about buffer solutions here https://brainly.com/question/8676275
#SPJ2
Which of the forces of molecular attraction is the weakest? A London dispersion forces B hydrogen bond C single covalent bond D dipole dipole interactions
Answer: London dispersion forces of molecular attraction is the weakest.
Explanation:
The forces which exist between neighboring atoms, molecules or ions can be force of attraction or force of repulsion. These forces are called intermolecular forces.
When ions with same charge come in contact with each other then force of repulsion is there but when ions with opposite charge comes in contact with each other then force of attraction will be there.
These forces are described as follows.
London dispersion forces: The electrostatic attraction between atoms or molecules causes a temporary induced charge on the respective atoms. These attractive forces are weak in nature and called London dispersion forces.
Hydrogen bond: When a hydrogen atom is attached to electronegative atom like fluorine, nitrogen and oxygen then bonding between these atoms is called a hydrogen bond.
Dipole-dipole interaction: When positive end of one polar molecule gets attracted by the negative end of another polar molecule then force existing between these ends is called dipole-dipole interaction.
Single covalent bond: When an atom is sharing its valence electrons with another atom then it is called a covalent bond.
Thus, we can conclude that London dispersion forces of molecular attraction is the weakest.
A hot metal plate at 150°C has been placed in air at room temperature. Which event would most likely take place over the next few minutes? Molecules in both the metal and the surrounding air will start moving at lower speeds. Molecules in both the metal and the surrounding air will start moving at higher speeds. The air molecules that are surrounding the metal will slow down, and the molecules in the metal will speed up. The air molecules that are surrounding the metal will speed up, and the molecules in the metal will slow down.
Answer:
last option is correct.
Air molecules surrounding the metal will speed up and metal molecules will slow down
Explanation:
the metal cools when placed in room temperature air which causes surrounding air to heat up.
the speed of molecules slow down for any material which cools and molecules speed increases when any material heats up