Which formula demonstrates a double replacement reaction?
1. A + B --> AB
2. AB + CD --> AC + BD
3. AB --> A + B
4. A + BC --> AC + B

Answer:

Refraction is the bending of a wave when it enters a medium where its speed is different, like going from the air (gas) to a glass of water (liquid). Absorption is when light energy penetrates an object. Typically this energy is then converted to heat.

Answer:

N₂O

Explanation:

Empirical formula is defined as the simplest whole number ratio of atoms presents in a molecule

For a nitrogen oxide that contains 63.66% of nitrogen, the percent of oxygen must be:

100-63.66 = 36.34% Oxygen

This percent is the percent in mass. To solve this question we must convert the mass of each atom to moles in order to find the simplest whole number ratio:

Moles of the atoms:

N = 63.66g * (1mol / 14g) = 4.547 moles N

O = 36.34g * (1mol / 16g) = 2.271 moles O

The ratio N:O is:

4.547 moles N / 2.271 moles O = 2

That means there are 2 atoms of N per atom of O and the empirical formula is:

Answer:

4- radioactive isotopes

Explanation:

I don't remember exactly but this question was on the regents

Uranium-238  is a non- fissile element. It is a radioactive isotope that can be best used to determine geological formations. Thus, option 4 is correct.

Radioactive isotopes are elements that have an unstable atomic nucleus and can undergo radioactive decay to produce new particles and energy. They have the same atomic number as that of their parent species.

Isobars are a substance that has atomic mass and do not include uranium. Nuclear fusion and fission are the processes of nuclear energy that combine or splits the unstable nucleus to form a new particle.

Therefore, option 4. Uranium-238 is a radioactive isotope.

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Speed

Explanation:

The distance travelled by a body per unit time

Answer:

The correct answer is Choice D.

(Headaches or backaches)​

Explanation:

Hope this helps!

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Answer:To be honest i dont know

Explanation:

e

Answer:

Explanation:

Alpha radiation ionizes the air. When smoke interaccts with the ionized particles it causes the alarm to sound.

Answer:

Problem: What is the effect of the amount of fish feed on the mass of goldfish?

Hypothesis: I think that feeding the goldfish four times a day will greatest increase in the mass of the goldfish.

Explanation:

The problem tends to ask question to which the research is conducted. It open ways for ideas towards a particular topic.

While the hypothesis is a tentative or assumed stand on a subject. It is further tested through an experiment or survey and if after many trials it gives same results and the obtained results is concordant with the hypothesis, the hypothesis will then become accepted and a theory or law is formed thereafter.

Answer:

85.5%

Explanation:

To get the experimental value, you need to convert 15.0 grams of Na2SO4 to grams of Na3PO4. You do this with stoichiometry.

Convert grams of Na2SO4 to moles with molar mass. Then convert to moles of Na3PO4 with the mole-to-mole ratio according to the balanced chemical equation. Then convert moles of Na3PO4 to grams with the molar mass.

15.0 g Na2SO4 x (1 mol/142.04 g) x (2 Na3PO4/3Na2SO4) x (163.94 g/1 mol) = 11.7 g Na3PO4

Percent Yield = (actual value/experimental value) x 100

Actual Value = 10.0 g

Experimental Value = 11.7 g

10.0g/11.7 g = 85.5%

Answer:

B. An equation that shows only those particles involved in the reaction, and that is balanced for both mass and charge

Explanation:

A net ionic equation is a chemical equation that will only show the elements, compounds, and ions that are directly involved in the chemical reaction. It comes from the balanced molecular equation and should be balanced by both mass and charge.

Answer:

c

Explanation:

Thermal Energy has been the type of energy that refers to the kinetic energy of particles contained in a system. Hence, the correct option is (C).

Thermal energy is the energy contained within a system as a result of its temperature. Thermodynamics, a branch of chemistry, states how heat is transmitted through multiple systems and how work is done in the process by the virtue of the first law of thermodynamics.

The thermal energy speeds the movement and collision of the particles present within the system. It is found in electric heat, geothermal, coals, etc. It is due to the kinetic energy that allows the movement of the particles.

Therefore, option C. the kinetic energy contained in the particles results in thermal energy.

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Answer: mass of water is 81.1 g

Explanation: from reaction eguation you see there are equal amounts of water and Mg(OH)2. Then amount of water is 4.50 mol. Molar mass of water is 18.016 g/mol.

Mass m= n·M= 4.50 mol· 18.016 g/mol = 81.1 g

The number of grams of water reacting to form a mass of water is 81.1 g.

Mass is the quantity of matter in a physical body.

The given reaction is

MgO(s) + H₂O(1) → Mg(OH)₂(s)

The number of moles is equal in both sides

The moles of water is 4.50

The molar mass of water is 18.016 g/mol

mass × molar mass

4.50 × 18.016 = 81.1 g.

Thus, the number of grams of water reacting to make a mass of water is 81.1 g.

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1= b. electrons are lost

2= a. after one substance is oxidized

In a collection of marbles, 25% of the marbles have a mass of 5.00 g and 75% of the marbles have a mass of 7.00 g. The average mass of a marble is 6.50 g.

Explanation:

a. CGS system: centimetre as the unit of length, the gram as the unit of mass, and the second as the unit of time

b. SI system: metre as the unit of length, the kilogram as the unit of mass, and the second as the unit of time

Answer:

1150g

Explanation:

The equation for producing sulphur dioxide is [tex]S + O_{2} ==> SO_{2}[/tex]

Looking at the ratios, you need 1 mole of sulphur for every 1 mole of sulphur dioxide

Sulphur dioxide has a molar mass of 32 + (2 x 16) = 64g

2.30 x 1000 = 2300

2300 / 64 = 35.9375

35.9375 x 32 = 1150g of sulphur

Answer:

See explanation

Explanation:

In ClNO , nitrogen is the central atom here. The central atom has a tetrahedral electron pair geometry and a lone pair on the nitrogen atom. Due to the lone pair, the electron pair geometry is now trigonal pyramidal.

The molecule CS2 has a linear molecular geometry. There are four electron groups around the central atom hence the electron pair geometry is tetrahedral but the molecular geometry results from the repulsion of the two double bonds.

The electron domain geometry for Cl2CO  is tetrahedral since there are four electron pairs around the central atom. However, the molecular geometry is trigonal planar due to the sp2 hybridization of the central carbon atom.

The electron domain geometry of Cl2SO  is tetrahedral due to the four electron pairs around the central atom. However, due to the lone pair on sulphur, the molecular geometry is  triagonal pyramidal.

In SO2F2, sulphur the central atom is surrounded by four electron pairs which are all bonding groups hence both the molecular geometry and the electron pair geometry is tetrahedral.

In XeO2F2, the central atom is Xe. There are five electron pairs around the Xe central atom four of which are bonding groups. The electron domain geometry and molecular geometry is trigonal bipyramidal.

For ClOF2 , the central atom Cl is surrounded by four electron pairs hence the electron pair geometry is tetrahedral but it is an AX3E(three bonding groups and one lone pair are present in the structure) specie hence it is trigonal pyramidal.

Answer:

CH3CH2CH3

(CH3)3CLi

CH3SNa

Explanation:

Answer: Both are compounds

Explanation:

[tex]\text{N}_{2}[/tex] is an element, not a compound.

Answer:

Limited Genetic Variability

Explanation:

its 3

A containment building.

hope this helpedddd

Answer:

A

Explanation:

Igneous rock forms from cooled lava

Answer:

It is 1,400 j

Explanation:

That is what i know

Answer:

1,400J

Explanation:

the formula for calculating Gravitational Potential Energy is mass×gravitational field strength×height

70×10×20=1,400

Answer:

V2O5 is the empirical formula of vanadium oxide

Explanation:

The molecular mass of Vanadium is  50.949 g/mol

Number of moles of vanadium = 0.3456 g/50.949 g/mol = 0.00696 moles

The molecular mass of Oxygen is 16.0 g/mol

Number of moles of Oxygen = (0.6330 – 0.354) g/16 g/mol = 0.0174 moles

Emperical formula  

V (0.00696 moles/0.00696 moles) O (0.0174 moles /0.00696 moles)

V 1 O2.5

Multiply by two get a whole number  

V2 O5

Answer:

165 ml

Explanation:

We are given;

Initial volume; V_a = 55 ml

Initial molarity; M_a = 3 M

Molarity of desired solution; M_b = 0.75 M

Volume of desired solution; V_b = (55 + x) ml

Where x is the volume of water to be added.

To solve for V_b, we will use the equation ;

M_a•V_a = M_b•V_b

V_b = (M_a•V_a)/M_b

V_b = (3 × 55)/0.75

V_b = 220 mL

Thus;

(55 + x) = 220

x = 220 - 55

x = 165 mL

Answer:

gotta concert mL to L

3.0=mol/0.055( you multiply morality and liter)

0.165 mol

you divide the mole by the other given molarity

0.165/0.75= 0.22 L

0.22 *1000= 220 mL

Explanation:

Answer:86.84

Explanation:

Answer:

An element's mass number (A) is the sum of the number of protons and the number of neutrons. The small contribution of mass from electrons is disregarded in calculating the mass number.

Answer:

ITS TRUE!!!!!

Answer:

A- Before the mechanic left, the molecules were moving away from each other. When she returned, they were moving around each other.

Explanation:

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