formal units are formed by?
Answer:
However, when formal units are used to measure length, the measurement can usually be read from a scale on a ruler or tape, which shows units of a particular size. Unit iteration involves knowledge of repeatedly placing identical tightly packing units so that there are no overlaps or gaps.
Explanation:
Does Rubidium (Rb) have high or low electronegativity?
Answer:
high
Explanation:
John is performing an experiment in which a solution alternates between a clear color and a bluish-purple color at a regular time interval. He observes that the time interval between color changes is 30 seconds (s). Sally replicates the experiment with the same solution, but at a temperature that is 10 degrees Celsius (°C) higher. What is the most likely time interval between color changes at this higher temperature? *
Answer:
15 sec
Explanation:
Sodium metal reacts violently with water and chlorine is a toxic gas, yet we eat sodium chloride. Why is this possible? Select one: a. The properties of compounds are different from the properties of the elements that form the compounds.
b. The properties of compounds are identical to the properties of the elements that form the compounds, and we should not eat sodium chloride because it is toxic.
c. The physical properties of compounds are different from the physical properties of the elements that form the compounds, but the chemical properties of the elements and compound are the same.
d. The chemical properties of compounds are different from the chemical properties of the elements that form the compounds, but the physical properties of the elements and compound are the same.
Answer:
The properties of compounds are different from the properties of the elements that form the compounds.
Explanation:
When elements form compounds, their properties are significantly modified. The physical and chemical properties of compounds and that of the elements that compose them are significantly different.
The introduction of chemical bonds between different atoms in compounds make the compounds to differ from elements where the atoms are bonded to atoms of the same element.
What is 13.48cm+7.6cm rounded to the correct number of significant figures?
Calculate the speed for a car that went a distance of 150 kilometers in 2 hours time. btw this is science
Answer:
The speed of the car is 75 km per hour
Explanation:
Speed is distance over time so 150 km divided by 2 hours is 75km per hour.
Please mark brainliest!!! Thanks.
Hydrogen bond is not formed by 1) oxygen 2) nitrogen 3) chlorine
PLEASE HELP!!!
i mean which cant form hydrogen bond
Answer:
Chlorine
Explanation:
Even though chlorine is highly electronegative, the best answer is no, and in this class we will consider chlorine not to form hydrogen bonds (even though it has the same electronegativity as oxygen). This is because chlorine is large and its lone electron is in a diffuse orbital, covering a large area, and thus do not have the high charge density to act as a strong hydrogen bond acceptor. But it does form weak hydrogen bonds in solid crystalline hydrogen chloride at very low temperatures.
Hi can someone help me with this question!
First one to answer it I will make u brainliest
Answer:
Test 2
Explanation:
............................................
Answer:
(B) Test 2
Explanation:
The entire substance changed, and turned into a liquid.
Darwin told us that science:
saves lives
Answer:yup!!
Explanation:
How many elements do all the “s” orbital span (go across) in each period?
a) 2
b) 6
c) 10
d) 14
The elements do all the “s” orbital span (go across) in each period is 2. Thus option a is correct.
What are elements?Elements are defined as a pure substance made up of only one sort of atom with the same number of protons in its nucleus.
It can also be defined as the a substance that can't be broken down into anything else.
Sublevels are defined as a quantum theory-defined energy level Sublevels are energies associated with electrons in chemistry.
There are mainly four sublevels
s sublevelp subleveld sublevelf sublevelThus, the elements do all the “s” orbital span (go across) in each period is 2. Thus option a is correct.
To learn more about elements, refer to the link below:
https://brainly.com/question/13025901
#SPJ2
Here is a model of the sun earth system at a certain point in earths orbit around the sun based on the model which statement best explains my point is is experiencing summer
Answer:
the earth is tilted towards the sun
Explanation:
In the context, there is a sun and earth system and at a certain point when the earth is moving in its orbit around he sun, some point on the earth experiences the summers season. This is because at this point of the earths revolution, the point on the earth is facing the sun and is also tilted towards the sun. So at this point the sun rays fall directly at the surface. While the place which is tilted away from the sun, experiences winter season.
Answer:
Earth's northern hemisphere is tilted toward the Sun.
During free fall which object would have a greater acceleration, an object with a mass of 240 kg or an object with a mass of 10 kg? Explain your answer.
Answer:
Leroy Jeakins
Explanation:
Catus jack f me in the asss
How does nano frabic work
Answer:
Nano silver is woven into fabric to give it anti-bacterial properties.
Explanation:
Helps by fending off the bacteria that make those clothes smell after you sweat. Nano-titanium dioxide adds sun protection to clothing just as it does in sunscreen. The use of nanoparticles to achieve fresh-smelling clothes and UV protection may not be safe.
A student observes that a popcorn kernel has a hard coat. He places the kernel in a moist paper towel and observes it for several days. He notices that the coat splits and a small root emerges. He concludes that
Answer: Water inside the seed coat creating a pushing force, breaking the seed coat.
Explanation:
Seed germination can be defined as the process by which a new plant emerge out from a seed. The radicle is the first emerging part from a seed and it develops into a root and the plumule is the second emerging part and it develops into a shoot. The light, water, adequate temperature, and soil are the factors that are necessary for seed germination.
According to a given situation, the popcorn kernel will receive the moisture necessary for the germination process, the water will imbibe into the seed coat creating pressure inside the seed and which will cause the seed coat to break and the new plant parts or seedling will emerge out of the seed coat.
Help please !
A
B
C
D
Answer:
the answer is letter B. the entropy
Which compound is
ionic?
Answer:
chemistry
Explanation:
How many elements are in H
a) 3
b) 2
c) 1
d) 5
Answer: C (1)
Explanation:
H is only the element hydrogen.
Is copper sulphate malleable?
Answer:
Yes, Copper (Cu) in its pure form is a reddish-brown metallic element with high ductility and malleability that is an excellent conductor of heat and electricity: atomic weight 63.54; atomic number 29; density 8.94 g/cm3; melting point 1083°C; and boiling point 2595°C.
Answer:
no ,its not malleable
Explanation:
copper II sulphate is a blue compound , which is brittle solid , crystalline .
copper metal is malleable and ductile
True or False;
aa is faster moving lava than pahoehoe?
Answer:
It is false :l
Explanation:
Pahoehoe is a smooth and continuous lava crust. Pahoehoe forms when the effusion rate is low and consequently the velocity of lava flow is slow. Pahoehoe lava flow is usually at least 10 times slower than typical aa lava flow.
:/
The total amount of energy before and after a chemical reaction is the same. Therefore, energy is _____.
created
destroyed
converted
conserved
Answer:
Option (a) is the correct answer.
Explanation:
The law of conservation of energy states that energy can neither be created nor it can be destroyed. It can only be transformed from one form to another.
Therefore, the total amount of energy before and after a chemical reaction is the same. Thus, energy is conserved.
Therefore, we can conclude that option (a) is the correct answer.
Answer:
conserved
Explanation:
law of conservation of energy says that energy can neither be created or destroyed
Helpppppp!!!!! It’s due today
URGENT!!!!!
Answer:
Explanation:
2. a [CO3 2-][H3O+] / [H2O][HCO3-
b. [H2PO4-][H3O+]/[H3PO4][H2O]
is xenon a metal and is Beryllium a metal
Answer:
No and yes
Explanation:
Xenon is a noble gas and beryllium is a metal
Answer: no and yes i also agree
Xenon is a noble gas and Beryllium a metal
Explanation:
A sealed can of soda contain a pressure of 1.15 atm at 23°C. What is the new pressure at 79 °C? Report your answer to the hundredths place (two decimal places) You do NOT need units in your answer
Answer:
P₂ = 1.37
Explanation:
Given data:
Initial pressure = 1.15 atm
Initial temperature = 23°C (23+273= 296 K)
Final pressure = ?
Final temperature = 79°C (79+273=352 K)
Solution:
According to Gay-Lussac Law,
The pressure of given amount of a gas is directly proportional to its temperature at constant volume and number of moles.
Mathematical relationship:
P₁/T₁ = P₂/T₂
Now we will put the values in formula:
1.15 atm / 296 K = P₂/352 K
P₂ = 1.15 atm × 352 K / 296 K
P₂ = 404.8 atm. K /296 K
P₂ = 1.37 atm
Ammonia is formed from the reaction of nitrogen and hydrogen according to the equation:
N2(g) + 3H2(g) 2NH3(g)
What is the maximum number of moles of ammonia that can be formed from the reaction of 27 moles of hydrogen?
A
41
B
27
18
D
9
Answer:
18 mol NH₃
General Formulas and Concepts:
Chemistry - Stoichiometry
Using Dimensional AnalysisExplanation:
Step 1: Define
RxN: N₂ (g) + 3H₂ (g) → 2NH₃ (g)
Given: 27 moles H₂
Step 2: Stoichiometry
[tex]27 \ mol \ H_2(\frac{2 \ mol \ NH_3}{3 \ mol \ H_2} )[/tex] = 18 mol NH₃
Step 3: Check
We are given 2 sig figs.
Since our final answer is in 2 sig figs, we do not need to round.
when a substance melts the kinetic energy
A Decreases then increase
B Decrease
C Stays the same
D Increase
Answer:
C stays The same.
Is the answer.
400 liters of a certain gas is collected at STP. What will the volume be at 273 C and 190 torr pressure?
Answer:
2.00 L of a gas is collected at 25.0°C and 745.0 mmHg. What is the volume at STP? STP is a common abbreviation for "standard temperature and pressure." You have to recognize that five values are given in the problem and the sixth is an x. Also ... 273 1. A gas has a volume of 800.0 mL at minus 23.00 °C and 300.0 torr.
Explanation:
If a neutral compound is composed of carbon and hydrogen and you know that it has exactly 2 carbons connected by a double bond, how many hydrogens will the compound have?
Answer: 4 hydrogens
Explanation:
This is what the structure will look like C=C. Remember that it's important that all structures have a complete octet. As it looks right now each carbon is sharing 4 valence electrons so each needs 2 more bonds to hydrogen complete its octet.
Answer: 4 hydrogens
Explanation:
For an object to remain at rest which of the following statements must be true
Answer:
An object that is at rest will stay at rest unless a force acts upon it. An object that is in motion will not change its velocity unless a force acts upon it. This is known as uniform motion. An object continues to do whatever it happens to be doing unless a force is exerted upon it.
Explanation: NEWTONS laws of motion
What is the molarity of a hydrochloric acid solution, when 30.0 mL is neutralized by 48.0 mL of 0.100 mol/L
calcium hydroxide?
The molarity of a hydrochloric acid solution : 0.32 M
Further explanationTitration is a procedure for determining the concentration of a solution by reacting with another solution which is known to be concentrated (usually a standard solution).
Titrations can be distinguished including acid-base titration, depositional titration, and redox titration. An acid-base titration is the principle of neutralization of acids and bases is used.
Acid-base titration formula
Ma. Va. na = Mb. Vb. nb
Ma, Mb = acid base concentration
Va, Vb = acid base volume
na, nb = acid base valence
1 ⇒HCl (valence=1, HCl ⇒H⁺+Cl⁻, one H⁺)
2⇒Ca(OH)₂(valence=2, Ca(OH)₂⇒Ca²⁺+2OH⁻, two OH⁻)
M₂=0.1 M
V₂=48 ml=0.048 L
V₁=30 ml=0.03 L
[tex]\tt M_1.V_1.n_1=M_2.V_2.n_2\\\\M_1\times 0.03\times 1=0.1\times 0.048\times 2\\\\M_1=0.32[/tex]
3. How many moles are in 1.49 x 1023 molecules of iodine?
Answer:
The answer is 0.25 molesExplanation:
To find the number of moles in a substance given it's number of entities we use the formula
[tex]n = \frac{N}{L} \\ [/tex]
where n is the number of moles
N is the number of entities
L is the Avogadro's constant which is
6.02 × 10²³ entities
From the question we have
[tex]n = \frac{1.49 \times {10}^{23} }{6.02 \times {10}^{23} } = \frac{1.49}{6.02} \\ = 0.247508305...[/tex]
We have the final answer as
0.25 molesHope this helps you