Which sentence describes existing cells?
All cells, once formed, continue to live forever.
All cells come from previously existing cells.
All the cells that are on Earth have always been here.
All cells develop from the remains of other cells.
how can we separate the sugar from sugar solution
the element of group 1 are reactive but those of group 18 are inert, why
Answer:
Because elements of group 1 does not have stable electronic configuration and elements of group 18 have stable electronic configuration.
Explanation:
Because elements of group 1 do not contain stable electronic configuration and elements of group 18 include stable electronic configuration.
What are the element of group 1?Group 1 elements contain the alkali metals, Li, Na, K, Rb, Cs, and Fr. The alkali metals exist all soft, shiny, and metallic when cut. They react efficiently with water, have low melting points and densities, and are good conductors of electricity. They all include one valence electron that they lose easily to form ions. Noble gas exists as any of the seven chemical elements that create up Group 18 (VIIIa) of the periodic table. The elements exist as helium (He), neon (Ne), argon (Ar), krypton (Kr), xenon (Xe), radon (Rn), and oganesson (Og).
The element of group 1 exist as reactive but those of group 18 exist as inert Because elements of group 1 do not contain stable electronic configuration and elements of group 18 include stable electronic configuration.
To learn more about element of group1 refers to:
https://brainly.com/question/2116245
#SPJ2
What is known about a reaction with a positive enthalpy?
Answer:
"Endothermic reaction: In an endothermic reaction, the products are higher in energy than the reactants. Therefore, the change in enthalpy is positive, and heat is absorbed from the surroundings of the reaction."
Explanation:
When enthalpy is positive and delta H is greater than zero, this means that a system absorbed heat. This is called an endothermic reaction. When enthalpy is negative and delta H is less than zero, this means that a system released heat. This is called an exothermic reaction.
What does a high positive enthalpy mean?
The sign of q for an endothermic process is positive because the system is gaining heat. A chemical reaction or physical change is exothermic if heat is released by the system into the surroundings. Because the surroundings are gaining heat from the system, the temperature of the surroundings increases.
Learn more about the endothermic reaction here: brainly.com/question/6506846
#SPJ2
Determine the grams of sodium chloride produced when 10 g of sodium react with 10 grams chlorine gas according to the equation 2Na + Cl2 = 2 NaCl
Answer:
16 g
Explanation:
Step 1: Write the balanced equation
2 Na + Cl₂ ⇒ 2 NaCl
Step 2: Identify the limiting reactant
The theoretical mass ratio (TMR) of Na to Cl₂ is 46:71 = 0.65:1.
The experimental mass ratio (EMR) of Na to Cl₂ is 10:10 = 1:1.
Since EMR > TMR, Cl₂ is the limiting reactant
Step 3: Calculate the mass of NaCl produced
The theoretical mass ratio of Cl₂ to NaCl is 71:117.
10 g Cl₂ × 117 g NaCl/71 g Cl₂ = 16 g NaCl
The atomic mass of calcium is calculated by adding the mass (amount) of
A) Protons and Electrons
B) Protons and Neutons
C) Electrons and Neutons
D) Protons and Protons
Answer:
B. Protons and Neutrons
Answer:
Option"B" is correct.
MARK ME BRAINLISTS
hii pls help me to balance the equation thanksss
▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓
[tex]\pmb{\red{\boxed{\sf{Na_{2}O(s)+H_{2}O(l)\dashrightarrow 2NaOH(aq) }}}}[/tex]
▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓
Identify an element as a metal or a non-metal according to its position in the Periodic
Table
Answer:
Metals on the left of the Periodic Table.
Non-Metals on the top-right, plus Hydrogen.
4. Calculate the relative molecular masses of the following substances [RAM: H=1, O=16, S=32, C=12, N=14] a. CH2(NH2)COOH b. H2SO4
Answer:
a. CH2(NH2)COOH
[tex]molecular \: mass = (12 \times 2) + (5 \times 1) + (14 \times 1) + (16 \times 2) \\ = 24 + 5 + 14 + 32 \\ = 75 \: grams[/tex]
b. H2SO4
[tex]molecular \: mass = (2 \times 1) + 32 + (16 \times 4) \\ = 2 + 32 + 64\\ = 98 \: grams[/tex]
If 16.4 grams of calcium nitrate is heated as shown in the reaction:
2Ca(NO3)2 -> 2CaO + 4NO2 + O2.
Calculate the volume of nitrogen dioxide produced at STP.
Answer:
7.2
Explanation:
you first have to find the number of moles of nitrogen dioxide by using the number of moles for calcium nitrate and the mole to mole ratios
number of moles of calcium nitrate=mass/mm
=16.4/102
=0.16g/mol
then you use the mole to mole ratios
2 : 4
0.16: x
2x/2=0.64/2
x=0.32g/moles of nitrogen dioxide
then you use the formula for the volume
v=22.4n
=22.4×0.32
=7.2
I hope this helps
Water glass is found in
A. Liquid form at room temperature
B. solid state at room temperature
c. semi liquid form at room temperature
D. None of above
Answer:
liquid form
Explanation:
am i right? if right like
Answer:
semi-liquid at room temperature
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
****************************************************************
******************* ijustwantthepoints *************************
value of MA is always lesser thàn 1 why?
Answer:
because the load arm is greater than the effort arm. As we know that when the load arm is greater than the effort arm, the mechanical advantage will always be lesser than one, which results in gain in speed
Which statement describes the periodic law?
Help please now!
Answer:
Answer is: elements in the same group have similar chemical properties. Periodic law is the arrangement of the elements in order of increasing atomic number.
Define physical and chemical properties, provide three examples of each, discuss their reversibility, and explain the fundamental differences between them.
Answer:
Physical properties are defined as the properties which can be observed without changing its chemical composition.
For example: color, volume, and molecular weight.
Chemical properties are defined as the properties which can be observed only after changing chemical identity of the substance.
For example: reactivity, toxicity, and flammability.
The fundamental differences between physical and chemical properties are as follows:
Chemical properties are related to chemical bonds of the substance while physical properties are not.
In chemical properties, chemical identity of substance changes while physical properties do not have any change.
Chemical properties predict the reaction of substance while physical properties only describe the appearance of the substance.
Explanation:
Answer:
A measurable property that can be observed typically and explains any matter or organism's appearance and physical behavior is called a physical property. Examples of physical properties are appearance, boiling point, freezing point, melting point, colors, odor, mass, density, solubility. Properties that are only observed during a reaction or change in the composition of a matter is called a chemical property. These properties describe the internal part of anything and explain how it behaves when reacted with other chemical substances. Examples are enthalpy, entropy, reactivity, flammability, oxidation state, acidity, basicity. Some physical properties are reversible or sometimes irreversible. Like the change of states of matter is reversible, and the growth of an organism is irreversible. The same thing with the chemical properties. There are reversible chemical reactions(formation of ammonium chloride) and irreversible chemical reactions. (burning of a chemical substance). After knowing all about these properties, the most fundamental difference is that the physical properties can be measured without any chemical change in them. But a chemical property is measurable when the substance goes through a chemical reaction.
Explanation:
How many times more acidic is pH2 than pH4?
Answer:
100 times more acidic.
Explanation:
If you look at the pH scale, pH2 is 2 "jumps" away from pH4, therefore, pH2 is 100x more acidic than pH4.
What process is used to refine aluminum from its ore bauxite?
A. Electrolysis
B. Electrolytic oxidation
C. Voltaic cell processing
D. Smelting
The correct option for the process used to refine aluminum from its bauxite ore is option D.
D. Smelting
The reason why smelting is the correct choice is as follows;
Bauxite is the aluminum ore from which alumina, also known as aluminum
oxide, Al₂O₃, is produced. Bauxite is extracted from the topsoil regions of
some subtropical and tropical regions, and the Bayer process is primarily
then used to produce alumina from the bauxite.
Aluminum is produced from the alumina by an aluminum smelting process
known as the Hall—Heroult electrolytic process which involves the use of a
carbon anode and direct current to produce aluminum by reducing the
aluminum oxide
Learn more about smelting process here:
https://brainly.com/question/3444206
PLZ HELP ME WITH MY WORK
Answer:
Explanation:
pretty sure its mixure.
Answer: Freezing point depression
Explanation:
freezing point depression is a phenomenon that describes why adding a solute or solvent results in the lowering of the freezing point of the solvent
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.
Assertion: Atomic mass of aluminium is 27 Reason: An atom of aluminium is 27 times heavier than 1 / 12th of the mass of the C – 12 atoms.
Answer:
i is the correct answer.
Explanation:
the RAM of aluminum is indeed 27. And since the RAM of substances are measured in terms of the C-12 isotope then R indeed explains why the RAM Al is 27.
what apparatus is used to investigate the conductivity of solutions
HELP . Read the following graduated cylinder.
Use this media to help you complete the question.
22.0 mL
22 mL
23.0 mL
22.5 mL
The volume of the liquid from the graduated cylinder is 22.5 mL
The last option (22.5 mL) is the correct option
The question seems to be incomplete
The image that completes the question is shown in the attachment below.
From the image, we observe that the liquid meniscus is between the 20 mL and 25 mL marks. That means the volume will lie in this range.
NOTE: The meniscus of a liquid is the upward or downward curve seen at the top of a liquid in a container.
The type of curve shown in the image is a concave meniscus and the volume of the liquid is read from the bottom of the curve.
To read the value from the graduated cylinder, we will first determine the difference between two consecutive lines. Between the 20 mL and 25 mL mark (two thick lines), we have 5 spaces separated by thin lines.
The measure between two consecutive lines is the difference between two thick lines divided by number of spaces between them
∴ The measure between two consecutive lines = (25mL - 20mL) ÷ 5
The measure between two consecutive lines = 5mL ÷ 5 = 1 mL
Now, to read the position of the liquid,
Starting from the 20 mL mark, the liquid exceeds two more lines + half way to the next line ( that is 2mL + 0.5 mL)
∴ The position of the liquid is 20 mL + 2mL + 0.5 mL = 22.5 mL
Hence, the volume of the liquid from the graduated cylinder is 22.5 mL
Learn more here: https://brainly.com/question/19240870
Answer:
The answer is 22.5 mL
Explanation:
I hope this helps you :)
Identify each transition in this flowchart as a chemical change or a physical change.
Answer:
so i think physical change
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.
differentiate between Physical and chemical changes
Answer:
In a physical change the appearance or form of the matter changes but the kind of matter in the substance does not. However in a chemical change, the kind of matter changes and at least one new substance with new properties is formed.
I HOPE THIS WILL HELP YOU IF NOT THEN SORRY HAVE A GREAT DAY:)Which statement is true about percent yield
Identify each of the highlighted materials as an element, a compound, or a mixture, and explain your reasoning.
Answer:
These are compounds.
Explanation:
As it is formed by chemically bonding of two elements C ( carbon) and H (hydrogen) .
Its not a mixture because mixture is Just dispersed of diferrent elements or a compound which are not in fix ratioAnswer:
Butane and benzene are both compounds. They contain multiple elements bonded together in a specific ratio. Kerosene and gasoline are mixtures because they are combinations of several compounds. Oxygen is an element because it is made up of only one type of atom.
Explanation:
why is unit of pressure called a derived unit ?? 2) how do you measure the volume of milk?
1. Unit of pressure called a derived unit because it is a combination of base units (kg·m^-1·s^·2).
2. We measure the volume of milk by a instrument called Milk Lactometer.
