Which of the following best describes the Earth's movement around the sun?

A)The Earth is closer to the sun in Summer than in Winter.

B)The Earth moves in a circular pattern around the Moon

C)The Earth's axis moves back and forth, resulting in different seasons

D)The Earth moves in an elliptical orbit around the sun

Answer:

The answer is endothermic

Make the moon smaller than the Earth.

Answer:

Electrons have a negative charge. The charge on the proton and electron are exactly the same size but opposite. Neutrons have no charge. Since opposite charges attract, protons and electrons attract each other.Hope that helps

Explanation:

Answer:

D. number of neutrons

Explanation:

Isotopes of the same element must have the same number of neutrons. Neutrons of an atom are the uncharged particles within the nucleus.

Isotopy is the existence of two or more atoms of the same element having the same atomic number but having different mass number due to the differences in the number of neutrons in their various nuclei.

Therefore, isotopes differs based on the number of neutrons they contain.

Answer:

D. number of neutrons

Explanation:

Two isotopes of the same element have the same number of protons in the nucleus, but differ in the number of neutrons. The nucleon number is equal to the total number of protons and neutrons in the nucleus. ... The atomic mass number A is equal to the total number of protons and neutrons.

The pressure of the gas = 40 atm

Given

200 ml container

P = 2 atm

final volume = 10 ml

Required

Final pressure

Solution

Boyle's Law  

At a fixed temperature, the gas volume is inversely proportional to the pressure applied  

[tex]\tt \rm p_1V_1=p_2.V_2\\\\\dfrac{p_1}{p_2}=\dfrac{V_2}{V_1}[/tex]

Input the value :

P₂ = P₁V₁/V₂

P₂ = 2 x 200 / 10

P₂ = 40 atm

The dog would not  be in the part of first trophic level of an energy pyramid.

Energy pyramid is defined as a model that show the flow of energy from one tropic or feeding level to next tropic or feeding level in an ecosystem.

There are basically three energy pyramid.

Trophic level is defined as the source based on their nutrition or food, organisms occupy a specific place in a food chain.

First trophic level contains only green plants and producers. Their plants and product where consumed by second level of organisms.

Thus, the dog would not  be in the part of first trophic level of an energy pyramid.

To learn more about energy pyramid, refer to the link below:

https://brainly.com/question/2837831

#SPJ5

15 grams of  NH3 can be dissolved

Given

50 grams of water at 50°C

Required

mass of NH3

Solution

Solubility is the maximum amount of a substance that can dissolve in some solvents. Factors that affect solubility  

We can use solubility chart (attached) to determine the solubility of NH3 at 50°C

From the graph, we can see that the solubility of NH3 in 100 g of water at 50 C is 30 g

So that the solubility in 50 grams of water is:

= 50/100 x 30

= 15 grams

Answer:

According to Bohr, the amount of energy needed to move an electron from one zone to another is a fixed, finite amount. ... The electron with its extra packet of energy becomes excited, and promptly moves out of its lower energy level and takes up a position in a higher energy level. This situation is unstable, however.

Answer:

reactants contain more energy in the decomposition reaction of sodium azide?

Explanation:

Answer:

mass pic is explanation hope it helps

Answer:

V= L × W × H so the answer is 240,000

Answer: helium has the largest first ionization energy, while francium has one of the lowest.

Explanation:

The ionization energy decreases from top to bottom in groups, and increases from left to right across a period. Thus, helium has the largest first ionization energy, while francium has one of the lowest.

Answer:

Helium has the highest

Explanation:

Answer:

SYMBOLS, FORMULAS AND MOLAR MASSES

OBJECTIVES

1. To correctly write and interpret chemical formulas

2. To calculate molecular weights from chemical formulas

3. To calculate moles from grams using chemical formulas

INTRODUCTION

Part I. Symbols and formulas

An element is a homogeneous pure substance made up of identical atoms. All matter is made

up of elements and, since chemistry is the study of matter, it is convenient to use symbols to represent

the elements rather than using the entire name.

By international agreement, specific symbols are assigned to each element (Note: This means

that while names of the elements vary with language, symbols are constant throughout the world.) Each

element is assigned a one- or two-letter symbol. The first letter is capitalized, the second (if there is

one) is not. While this often seems trivial, it is in fact a very important point. For example, in chemical

language Co represents cobalt, which is a metal and an element, while CO represents carbon monoxide,

a compound which is a colorless, odorless gas! Even when there is not an obvious correspondence,

for instance "MN", it can cause confusion. Do you mean the element manganese? Did you forget a

letter and mean something else? Are you using "M" to represent something else entirely? Chemists

sometimes use "M" to represent any metal. It is well worth the trouble to memorize the symbols for

common elements.

Since compounds consist of elements, the chemical formulas of compounds also consist of

elements with subscripts used to denote the number of atoms per molecule. If there is no subscript, it is

implied that there is one of that kind of atom. Ones never appear in chemical formulas. Not only do

subscripts denote ratios of atoms, they also denote the ratio of moles of element to one mole of

compound. Parentheses can be used to show groups of atoms, with the subscripts showing how many

groups there are. Parentheses are not used if there is only one group.

Examples: For one mole of the following compounds, how many moles of each element are

present?

MgCl2 1 mole Mg, 2 moles Cl

Mg(NO3)2 1 mole Mg, 2 moles N, 6 moles O

NaNO3 1 mole Na, 1 mole N, 3 mole O

AgCl 1 mole Ag, 1 mole ClPart II. Molar Masses

Each atom has a different size and therefore a different mass. The relative masses of each

element can be found on the periodic table. For example, one atom of magnesium weighs 24.31 amu

(atomic mass units). However, one mole of magnesium weighs 24.31 g. (Moles were planned that

way!) Since one mole of MgCl2 consists of one mole of magnesium and two moles of chlorine, the

mass of one mole of MgCl2 must be the sum of the masses of the elements. The mass of one mole of a

substance is called the molar mass or molecular weight.

Examples: What is the molar mass of the following compounds?

MgCl2 24.31 + 2(35.45) = 95.21 g/mol

Mg(NO3)2 24.31 + 2(14.01) + 6(16.00) = 148.33 g/mol

NaNO3 23.00 + 14.01 + 3(16.00) = 85.01 g/mol

AgCl 107.9 + 35.45 = 143.4 g/mol

(Note: Yes! You DO have to count significant figures when calculating molecular weight/molar

mass. However, the number of significant figures may vary depending on which periodic table you use.)

Chemists are generally interested in number of moles. Unfortunately, it is impossible to measure

moles directly. However, masses are easily measured, and if the chemical formula of the compound is

known, the molar mass can be used to determine the number of moles. The molar mass is defined as:

molar mass = grams/moles = g/mol (1)

Moles may be calculated by using molar mass as a conversion factor in dimensional analysis where

molar mass in grams = 1 (exactly) mole of compound (2)

This method is used in multi-step calculations. For example, if 0.873 g of MgCl2 is weighed out, it

is 9.17 x 10-3

moles.

1 mole

0.873g x 95.21 g = 9.17 x 10-3

mol MgCl2 (3)

However, 0.873 g of AgCl is only 6.09 x 10-3

mol.

1 mole

0.873g x 143.4 g = 6.09 x 10-3

mol AgCl (4)Molar mass may also be used to relate moles to grams. For example, 0.158 mol of MgCl2 is 15.2 g.

0.158 mol x 95.21 g = 15.2 g MgCl2 (5)

1 mol

Percent is used to express parts per one hundred. Usually in chemistry, it refers to

g of species of interest x 100 = % (6)

g of whole thing

Example: For the % Mg in MgCl2: In one mole of MgCl2, there are 24.31 g of Mg (molar mass of Mg,

the part we are interested in) and 95.21 g of MgCl2 (the whole thing), so %Mg in MgCl2 is

(24.31/95.21) x 100 = 25.53% Mg (7)

PROCEDURE

Work individually.

The formula for calcium phosphate is Ca3(PO4)2. Weigh about 2 g of calcium phosphate to the

nearest 0.001 g. In other words, you do not have to have exactly 2.000g, but you must know the

weight you have exactly. Acceptable results include but are not limited to: 1.985g , 2.035g, 2.314g

etc.

Be sure to report all results with the correct number of significant figures and appropriate units!

Answer:18.015 g

Explanation:

Water has a molar mass of 18.015 g/mol . This means that one mole of water molecules has a mass of 18.015 g . So, to sum this up, 6.022⋅1023 molecules of water will amount to 1 mole of water, which in turn will have a mass of 18.015 g

[tex]\tt =3000~L\times \dfrac{289}{312}\times \dfrac{99}{45.5}[/tex]

Given

3000 L of gas at 39°C and 99 kPa to 45.5 kPa and 16°C,

Required

the new volume

Solution

Combined with Boyle's law and Gay Lussac's law  

[tex]\tt \dfrac{P_1.V_1}{T_1}=\dfrac{P_2.V_2}{T_2}[/tex]

T₁ = 39 + 273 = 312

T₂ = 16 + 273 = 289

Input the value :

V₂ = (P₁V₁.T₂)/(P₂.T₁)

V₂ = (99 x 3000 x 289)/(45.5 x 312)

or we can write it as:

V₂ = 3000 L x (289/312) x (99/45.5)

Answer:

2,909 M

Explanation:

molair mass is of.ethylene is 26,04 g/mol

first you need to calculate how much mL 3 kg is. You can do this by using the density of ethylene: 1,1 g/mL.

3000 g x 1.1 = 3300 mL = 3,3 L

Next you need to calculate the amount of moles:

250 g / 26,04 g/mol = 9,60 mol

Now you can calculate the molarity:

9,6/3.3 = 2,909 M

I don't know the answer for the second question. I'm sorry.

Answer:

i wish i know

Explanation:

Answer:

An orbit is a fixed path around the nucleus where an electron must be found; an orbital is a probability region where an electron is likely (but

not necessarily) going to be found

Explanation:

Orbits are fixed elliptical paths where an electron must be found. The idea of orbits was introduced in the Bohr model of the atom. Electrons were shown to occupy fixed orbitals of quantized energy.

Orbital is an idea introduced by quantum mechanics. It refers to a region in space where an electron may be found. The wave mechanical approach does not view the electron as being found in a fixed orbital but rather defines a region in space around the nucleus where there is a high probability of finding the electron.

Answer:

Natural Resource

Explanation:

A natrual resource is something that was created when Earth was first made. They were intended to fulfill human needs when they needed them. An example of a natural resource can be water, because we will need water to survive.

Answer:

ih2706

Explanation:

Answer:

Argon is a chemical element with the symbol Ar and atomic number 18.

Explanation:

Answer:

Avogadro's number is a very important relationshiptoremember: 1 mole = 6.022×1023 6.022 × 1023atoms, molecules, protons, etc.

...

Explanation:

jayfeather friend me

Answer:

you are right

Explanation:

C6H1206 is a compound (of glucose).

Answer:

magesium di chloride

Explanation:

it has one magnesium and 2 chlorines

Answer:

Magnesium Chloride

Answer:

The unit is: Newton.

Hope it helps:D