Isotopes are atoms that have the same mass number, but different numbers.
atomic. True or false
Answer: Im not sure but I think it is false.
Explanation:
what is the material used to make plaster of paris?
Answer:
gypsum
Explanation:
gypsum is used to make plaster of Paris
Answer:
Simple squamous epithelium
This type of epithelia lines the inner surface of all blood vessels (endothelium), forms the wall of alveolar sacs in the lung and lines the body cavities (mesothelium). The primary function of simple squamous epithelia is to facilitate diffusion of gases and small molecules.
Explanation:
isme talk kro
why can't sodium salt be prepared by double decomposition
Sodium salt might not be prepared by double decomposition because the method is used in preparing insoluble salts.
What is Double decomposition method?Double decomposition method serves as the method that is used in preparing compounds which entails reaction between two soluble compounds and after reaction soluble and insoluble products are produced.
Therefore, since most of the sodium salt are soluble salt , Double decomposition cannot be used to prepare them.
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Describe the principle and process for the manufractured of sulphuric acid witha a well labeled diagram by contact process.
The steps involved in the manufacture of sulphuric acid by contact process:
(1) Sulphur (or iron pyrites) are burnt in air to form sulphur dioxide.
S+O2→SO24FeS2+11O2→2Fe2O3+8SO2
(2) Catalytic oxidation of sulphur dioxide to sulphur trioxide.
2SO2+O2V2O52SO3ΔrHo=−196.6kJ
The reaction is reversible and exothermic.
(3) Sulphur trioxide is dissolved in 98% sulphuric acid to form oleum (fuming sulphuric acid).
SO3+H2SO4→H2S2O7
(4) Oleum is diluted with water to form sulphuric acid of desired concentration.
H2S2O7+H2O→2H2SO4
and
Manufacture of H2SO4 by contact process involves three steps:
1. Burning of sulphur in air to generate SO2.
2. Conversion of SO2 to SO3 by oxidation with air in the presence of
Need help with this
Answer:
H20is water andN20is nitrogen 4 oxide
convert the following into Kelvin scale 253°c
Explanation:
253°C + 273.15 = 526.15K
526.15 kelvins
state the modern periodic law
Answer:
The modern periodic law states that the physical and chemical properties of the elements are the periodic function of the atomic numbers and electronic configurations. ... This repetition occurs if the arrangement of the elements is in order of their increasing atomic numbers.
9. a) Name salt that can be prepared by precipitation
I think its the substances that sublimes
what’s the name of the organic molecule
Answer:
hexane
Explanation:
This is a 6- carbon hydrocarbon with no multiple bonds or any functional groups (such as -OH). Thus, the prefix 'hex' refers to the 6 carbons and 'ane' refers to the molecule being an alkane.
Naming molecules:
Number of carbons
• pentane: 5 carbons
• hexane: 6 carbons
• heptane: 7 carbons
• octane: 8 carbons
• nonane: 9 carbons
Functional groups (for 6- carbons molecules)
• Alkene (C=C): hexene
• Alcohol (-OH): hexanol
• Alkyne (C≡C): hexyne
which of the following has more atoms 3.14 g Cu or 1.10 g of H? Explain
Please help :)
A chocolate chip cookie recipe calls for 0.050 moles of baking soda (NaHCO3). How many grams should the chef mass out?
According to the mole concept, 4.2 g of baking soda should be weighed out.
What is mole concept?Mole is defined as the unit of amount of substance . It is the quantity measure of amount of substance of how many elementary particles are present in a given substance.
It is defined as exactly 6.022×10²³ elementary entities. The elementary entity can be a molecule, atom ion depending on the type of substance. Amount of elementary entities in a mole is called as Avogadro's number.
It is widely used in chemistry as a suitable way for expressing amounts of reactants and products.For the practical purposes, mass of one mole of compound in grams is approximately equal to mass of one molecule of compound measured in Daltons. Molar mass has units of gram per mole . In case of molecules, where molar mass in grams present in one mole of atoms is its atomic mass.
Baking soda has molar mass of 84 g /mole, thus mass is calculated using number of moles formula which is mass= molar mass×number of moles, which is mass=84×0.050=4.2 g.
Thus,4.2 g of baking soda should be weighed out by chef.
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2. Low-density polyethylene, used to make plastic films, is
made by the radical polymerization of ethene, and is one of
the hardest plastics to recycle. It gets its name
A. from the process by which it's polymerized.
B. because of the way the chains pack like spaghetti, close
and tight.
C. from the spaces left between chains when the polymer is
formed.
D. because it's strong but flexible.
Answer:
from the spaces left between chains when the polymer is
formed.
Explanation:
Polyethylene polymer may be of high or low density. Whether the polymer is of high or low density depends on the arrangement of the polymer chains.
If the polymer chains are close together such that the resultant polymer is crystalline with chains packed closely, we have high density polyethylene.
On the other hand if the chains are not close together and there are spaces left between chains when the polymer is formed, then we have low density polyethylene.
Hence, low density polyethylene gets its name from the spaces left between chains when the polymer is formed.
Answer: it gets its name (from the process by which it's polymerized). Therefore the correct option is A.
Explanation:
Polyethylene is a type of plastic which is made by the polymerization of its monomers (ethene). The most common monomers are derived from petrochemicals. The monomers simply join together to form the polymers which has the same empirical formula as the monomer, but is of a higher molecular mass.
There are two main types of polyethylene, these include:
--> Low density polyethylene: when ethene is subject to a high temperature of about 250°C and pressure above 1500atm, together with traces of oxygen ( as an initiator), it polymerizes to polyethylene. The polyethylene obtained by the above method is called a low density polyethylene. It has the most long- and short-chain branching of any form of polyethylene, resulting in its lower density. Therefore its name is gotten from the process by which it's polymerized
--> High density polyethylene: this is prepared at a lower temperature and pressure by using catalysts.
PLZ HELP What is an electron? O A.
A positively charged particle
B. An element on the periodic table
C. A negatively charged particle
D. A particle found in the nucleus SUBMIT
Answer:
C
electrons are negatively charged particles
Answer: D
Explanation:
just took the test
4.1 shows a plant cell. g For Examiner's Use n. C D Fig. 4.1 (i) Name the type of plant cell shown in Fig. 4.1. [1]
Answer:
palisade cell due to presence of chloroplasts
9.0 mol of pure ammonia gas was injected into a 3.0 L flask and allowed to reach equilibrium according to the equation 2 NH3(g) = N2(g) + 3 H2(g). The equilibrium mixture was analyzed and found to contain 3.0 mol of hydrogen gas. Calculate the value of the equilibrium constant.
NOExplanation:
I DONT KNOW MATE
How many Sodium (NA) Atoms are in Calcium Oxide
Answer:
2 Na atoms
Explanation:
hii pls help me to balance the equation thanksss
Answer:
3Fe(s)+2O2(g)---->Fe3O4
this way you will have 3irons on both sides and 4 oxygens.
I hope this helps
▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓
[tex]\boxed{\pmb{\red{\sf{3Fe(s) + 2O_{2}(g)\dashrightarrow Fe_{3}O_{4}(s)}}}}[/tex]
▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓
For the reaction 2HNO3 + Mg(OH)2 + Mg(NO3)2 + 2H20, how many
grams of magnesium nitrate are produced from 3.54 mol of nitric
acid, HNO3?
O a. 220
O b. 263
O c. 1050
O d. 175
Answer:
B
Explanation:
When a leaf of fresh sage or mint is rubbed ,the fragrance is
immediately obvious. Write a theoretical explanation for this observation
Answer: Volatile compounds present in the fresh sage leaf or mint leaf evaporate on rubbing.
Explanation:
When fresh sage or mint is rubbed on the skin or any other surface the volatile chemicals associated with the integral structure of the plant part get evaporated in the surrounding air and the vapors can be detected by the olfactory receptors present in the nose. These receptors take the smell or fragrance stimulus and generate impulses or signals which goes to brain and brain interprets the smell or fragrance.
Blood test can be used to check a person's blood glucose and hormone levels. The tabular column given below shows the result of two blood tests carried out on three people to check their blood glucose levels. Person 1 is healthy.
A:- Compare the glucose levels of person 1 with the glucose levels of person 2 after fasting for 12 hours.
B:- Compare the glucose levels of person 3 with the glucose levels of person 1, 2 hours after drinking 75g glucose.
C:- Person 3 cannot be produce the hormone that control blood glucose levels. State the hormone that person 3 cannot produce.
( THE ORDER OF THE PHOTO IS:- person 1, and person 2, and person 3)
Pls it is urgent
Answer:
Explanation:
1) person 2 had a slightly higher blood glucose level than person 1 after fasting 12 hrs (0.2mmols)
2) person 3 has a much higher blood glucose level than person 1 after taking glucose (5.6mmols)
3) insulin
8 - Escriba la fórmula del siguiente compuesto nitrogenado
Dietil benza amida
Answer:
Ver explanación e imagen adjunta.
Explanation:
El compuesto se conoce generalmente como N, N-dietilbenzamida.
Es una amida porque tiene la fórmula general RCONR.
La molécula se llama N, N-dietil benzamida porque los dos grupos etilo están unidos al átomo de nitrógeno como se muestra en la molécula.
Precipitate WILL form if Silver Nitrate reacts with Iron (III) chloride
-true or false
Answer:
yes
Explanation:
3Ag(No3) (aq) +FeCl3(aq) -->Fe(NO3)3(aq)+3AgCl(s)
How many liters are in 4.5 moles of CO2 gas at STP? Pls help :)
Answer:
Explanation:
NCO 2= 4,5
VCO2= 4,5* 22,4=100,8
Describe all the types of chemical reactions with example.
which elements total number of electrons is equal to the number of core electrons in barium(Ba)?
Answer:
Xenon
Explanation:
The core electrons of an element are the electrons that do not take part in the chemical reactions of the element
The electronic configuration of barium Ba is presented as follows;
1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d¹⁰ 4p⁶ 5s² 4d¹⁰ 5p⁶ 6s²
2+2+6+2+6+2+10+6+2+10+6
The valence electrons of boron are the 6s² electrons
The core electrons of boron are the; 1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d¹⁰ 4p⁶ 5s² 4d¹⁰ 5p⁶
The electronic configuration of xenon, Xe, which is the previous noble element before barium, is presented as follows;
1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d¹⁰ 4p⁶ 5s² 4d¹⁰ 5p⁶ which is the same as the core electrons of barium
Therefore, the total number of electrons in xenon is equal to the number of core electrons in barium
Imagine a substance that is a red, shiny solid at room temperature, with a melting point of 115 °C. It is brittle and a poor conductor of heat. State whether this substance is a metal or a non-metal. Give a reason for your answer.
Explanation:
Metals and non-metals can be identified either by their position in the periodic table or by their properties.
he metal elements are found on the left hand side of the periodic table, and the non-metal elements are found on the right. You can imagine a zig-zag line, starting at B-Al-Si, separating metals from non-metals.
When a solid dissolves in a liquid, it is termed
Answer:
Soluble
Explanation:
hope this helps
hii pls help me to balance the equation and state the symbols thanksss
Explanation:
2Fe (s) + 3Cl2 (g) = 2FeCl3 (s)
While driving her car on a hot sunny day, a woman was struck in the back of the neck by the dough from an exploding can of Pillsbury biscuits. From the sound it made and the feeling of warm sticky dough on her neck, she thought she had been hit by a bullet! Describe the likely conditions that caused this to happen. Be sure to explain AT THE MICRO scale how the particles were affected.
Answer:
The dough is made from flour sugar, baking soda, sometimes yeast. The sugar is converted into gaseous products including carbon dioxide, CO₂ and alcohols. As more gases are produced, the pressure increases, and according to Charles's law, as the temperature on a sunny day is higher than on a cool day, the pressure of the gases increases further, to the point that the can containing the biscuits can not hold the pressure, leading to an explosion
Explanation:
define measurment and its importance
Answer:
Explanation:
A measurement is the action of measuring something, or some amount of stuff. So it is important to measure certain things right, distance, time, and accuracy are all great things to measure. By measuring these things or in other words, by taking these measurements we can better understand the world around us.
Answer:
Measurement is the process of comparison of an unknown physical quantity with a known physical quantity.
It is important because measurement is needed in every day life we need measurement in simply cooking food to designing a house and many more other works.
Explanation:
hope this helps you.
