Standard temperature and pressure are

A. 0°C and 1.00 kPa
B. 0°C and 101.3 kPa
C. 273°C and 1.00 kPa
D. 273°C and 101.3 kPa

Answer:

Answer:

Birds evolved from a group of meat-eating dinosaurs called theropods. That's the same group that Tyrannosaurus rex belonged to, although birds evolved from small theropods, not huge ones like T. rex.

Answer:

we haven't done anything to study the roots of the bird yet

Answer:

4. 125°C

Explanation:

I hope this helps you :D

Answer:

Explanation:can you take a pic of it a little up so i can see the h please??

Answer:

graphite

Explanation:

graphite is also good conductor of electricity

Answer:

40.06

Explanation:

(23 * 39) + (48 * 40) + (29 * 41)

                   100

= 40.06

formula:

(% of isotope A * mass of A) + (% of isotope B * mass of B) ......

                                        100

Answer:

yes it can be broken down

Answer:

nuclear war ;P

Explanation:

Answer:

A. Florine has a stronger pull than Magnesium

Explanation:

Electronegativity refers to the tendency in which an tom would attract electrons to itself.

Below each element in the periodic table is their electronegativity value. Florine has the highest electronegativity value of 4.0.

Going through options;

A. Florine has a stronger pull than Magnesium

Florine = 4.0

Magnesium = 1.2

This correct

B. Hydrogen has a stronger pull than Phosphorus

Hydrogen = 2.1

Phosphorus = 2.1

This is wrong

C. Potassium has a stronger pull than Sodium

Potassium = 0.8

Sodium = 0.9

This is wrong

D. Iron has a stronger pull than Bromine

Iron = 1.8

Bromine = 2.8

This is wrong

Answer:

The abundance of 35/17 Cl is 75% and 25% of 37/17Cl

Explanation:

The molar mass of an atom is defined as the sum of the masses of each isotope times its abundance, that is:

35.5amu = 35amu*X + 37amu*Y (1)

Where X is the abundance of the 35/17Cl and Y the abundance of 37/17 Cl

As there are just these 2 isotopes and the abundances of both isotopes = 1:

X + Y = 1 (2)

Replacing (2) in (1):

35.5 = 35X + 37(1-X)

35.5 = 35X + 37 - 37X

-1.5 = -2X

X = 0.75 = 75%

And Y = 100-75% = 25%

Answer:

1. 7.227x10²⁴ O atoms

2. 0.1944 mol

3. 3.18x10²³ atoms

Explanation:

1. To solve this problem we need to use Avogadro's number, which states the number of molecules that are in 1 mol of a substance:

There are 3 O atoms per NaNO₃ molecule, thus the answer is (3* 2.409x10²⁴) 7.227x10²⁴ atoms.

2. First we convert 10.5 g of N₂O₅ into moles, using its molar mass:

There are 2 N moles per N₂O₅ mol, thus the answer is (2*0.0972) 0.1944 mol.

3. First we convert grams into moles:

Then we use Avogadro's number:

There are 14 O atoms per Fe(H₂O)₂(SO₄)₃ molecule, so the answer is (7.95x10²² * 4) 3.18x10²³ atoms.

Answer:

The unbalanced chemical equation is;

C. N₂O₅ + H₂O → HNO₃

Explanation:

In balancing a chemical reaction equation, only the coefficients of the terms of the reactants and/or the products are adjusted (and not the subscripts to the atoms in the compounds) to ensure that the total number of each element is the same on either side of the arrow for the chemical reaction

A coefficient term is the number multiplier of the compounds and elements in a chemical reaction

Therefore, the balanced chemical equation is obtained by changing the coefficient of the product from the implied '1' to a '2' as follows;

N₂O₅ + H₂O → 2HNO₃

do the yoga boi TUT yooooooooooooooooooooo9ooooooooot

Answer:

Lighting Bunsen Burner:

Explanation:

Close needle valve and collar. Open gas valve fully. Open needle valve 1/2 turn. Use the spark/lighter to light the flame.

Answer:

The nucleus consists of 4 protons (red) and 5 neutrons (orange). Four electrons (white) occupy available electron shells (rings). The stability of an element's outer (valence) electrons determines its chemical and physical properties. Subatomic particles are particles that are smaller than the atom. Protons, neutrons, and electrons are the three main subatomic particles found in an atom. Protons have a positive (+) charge. An easy way to remember this is to remember that both proton and positive start with the letter "P."

hope this helped:)

brainliest?

A beryllium atom has atomic number 4 where its nucleus has 4 protons  and 5 neutrons  and 4 electrons revolving around the nucleus in in the shells.

An atom is defined as the smallest unit of matter which forms an element. Every form of matter whether solid,liquid , gas consists of atoms . Each atom has a nucleus which is composed of protons and neutrons and shells in which the electrons revolve.

The protons are positively charged and neutrons are neutral and hence the nucleus is positively charged. The electrons which revolve around the nucleus are negatively charged and hence the atom as a whole is neutral and stable due to presence of oppositely charged particles.

Atoms of the same element are similar as they have number of sub- atomic particles which on combination do not alter the chemical properties of the substances.

Learn more about atom,here:

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Answer: b

Explanation:

Answer:

R is universal gas constant

It is has fixed value which would depend upon the units in which P,V and T expressed in the equation PV=nRT

R=

nT

PV

Answer:

value of R=0.0821atm,mol-¹k-¹

Answer:

bipetal

Explanation:

this is because 2 electrons will be donated by each element, as seen in NO2

Answer:

v = 16 m/s

Explanation:

Given that,

Distance, d = 400 m

Time taken, t = 25 s

We need to find the speed of the horse. Speed is equal to distance covered divided by time taken. So,

[tex]v=\dfrac{d}{t}\\\\v=\dfrac{400\ m}{25\ s}\\\\v=16\ m/s[/tex]

So, the speed of the horse is 16 m/s.

Answer: AgF

Explanation: 85 / 108 (the relative atomic mass of Ag) = 0.79

15 / 19 (the RAM of F) = 0.79

This is a 1:1 ratio so the empirical formula is AgF.

AgF is the empirical formula of a compound that contains 85% Ag and 15% F by mass.

A mole is defined as 6.02214076 × [tex]10^{23}[/tex]of some chemical unit, be it atoms, molecules, ions, or others. The mole is a convenient unit to use because of the great number of atoms, molecules, or others in any substance.

Molar mass of Ag =108 amu

[tex]Moles = \frac{mass}{molar \;mass}[/tex]

85 ÷ 108  = 0.79

The molar mass of F = 19amu

[tex]Moles = \frac{mass}{molar \;mass}[/tex]

15 ÷ 19  = 0.79

This is a 1:1 ratio so the empirical formula is AgF.

Hence, AgF is the empirical formula of a compound that contains 85% Ag and 15% F by mass.

Learn more about moles here:

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Answer:

B

Explanation:

IM A CHEMISTRY WIZZZZ

:)

I hope u get full marks on your paper/test/quiz or whatever!

There is a 20 percent chance so stay positive!

Answer:

D

Explanation: ultraviolet rays are harmful to humans

Answer:

H

Explanation:

b/c the polyatomic PO4¯³

have 3 valance number

Answer:

D. Compounds

Explanation:

Because it's says that have 3 components

Answer:

A. Empirical formula => C₂H₄O

B. Molecular formula => C₄H₈O₂

Explanation:

From the question given above, the following data were obtained:

Mass of C = 0.273 g

Mass of H = 0.046 g

Mass of O = 0.182 g

Molar mass of compound = 88 g/mol

A. Determination of the empirical formula of the compound.

C = 0.273 g

H = 0.046 g

O = 0.182 g

Divide by their molar mass

C = 0.273 /12 = 0.023

H = 0.046 /1 = 0.046

O = 0.182 /16 = 0.011

Divide by the smallest

C = 0.023 / 0.011 = 2

H = 0.046 / 0.011 = 4

O = 0.011 / 0.011 = 1

Thus, the empirical formula of the compound is C₂H₄O

B. Determination of the molecular formula of the compound.

Empirical formula = C₂H₄O

Molar mass of compound = 88 g/mol

Molecular formula =?

Molecular formula = [C₂H₄O]ₙ

[C₂H₄O]ₙ = 88

[(12×2) + (4×1) + 16]n = 88

[24 + 4 + 16]n = 88

44n = 88

Divide both side by 44

n = 88 / 44

n = 2

Molecular formula = [C₂H₄O]ₙ

Molecular formula = [C₂H₄O]₂

Molecular formula = C₄H₈O₂

Answer:

mechanical energy to electrical energy to light energy

Answer:

I mean i dont know......

Explanation:

Answer:

40.3044 g/mol

Explanation:

Answer:

Niches

Explanation: