The helium flash converts helium to the heavier element ____

atroni [7]

1) we can calculate the molecular weight of H₃PO₄
atomic mass (H)=1 amu
atomic mass (P)=31 amu
atomic mass (O)=16 amu

molecular weight (H₃PO₄)=3(1)+31+4(16)=98 amu.

1 mol (H₃PO₄)=98 g
1 mol= 6.022 * 10²³ molecules.

2) we calculate the mass of 4.00*10²³ molecules.

98 g-------------------6.022*10²³ molecules
x------------------------4.00*10²³ molecules

x=(98 g * 4.00*10²³ molecules) / 6.022*10²³ molecules≈65 g

Answer: 65 g

5 0

4 years ago

Which of the following can form a hydrogen bond with the HF molecule?

Lostsunrise [7]

Answer:

helium

(He)

Explanation:

helium

(He)

6 0

3 years ago

Convert 98.7 °F to Celsius Formula for Fahrenheit to Celsius

dmitriy555 [2]

Answer:

$\boxed {\tt 37.0555556 \textdegree C}$

Explanation:

The formula to convert Fahrenheit to Celsius, use the following formula.

$C=(\textdegree F -32)*\frac{5}{9}$

We want to convert 98.7 degrees Fahrenheit to Celsius, so we must substitute 98.7 in for degrees Fahrenheit.

$C=(98.7 -32)*\frac{5}{9}$

Solve inside the parentheses. Subtract 32 from 98.7.

$C=(66.7)*\frac{5}{9}$

Multiply 66.7 by 5/9.

$C=37.0555556$

98.7 degrees Fahrenheit is equal to 37.0555556 degrees Celsius

3 0

4 years ago

Read 2 more answers

O

viva [34]

Answer:

The second and third option are isotopes of Bromine

Z= 35 A = 79

A = 79 N= 44

Explanation:

Step 1: What are isotopes ?

⇒ Elements with same atomic number (Z) ( this means the same number of electrons and protons) but a different number of neutrons (N)

The atomic number (visible on the periodic table) is the number of protons.

The atomic mass is the sum of the protons (Z) and neutrons (N), and is showed as 'A'. So A = Z+N

If we look at the periodic table, we can see that the atomic number of bromine (Z) = 35. This means the amount of protons = 35. Since isotopes have the same amount of protons, all isotopes of bromine, have 35 protons.

1) Z = 79, A = 196

Z = protons = electrons .So this element has 79 protons, as well as 79 electrons.

196 = 79 + N ⇒ N = 196 - 79 = 117 neutrons

⇒Since it doesn't have 35 protons, it isn't an isotope of Bromine, but of Gold (Au): 196Au

2) Z = 35 , A = 79

Z = protons = electrons .So this element has 35 protons, as well as 35 electrons.

79 =35 + N ⇒ N = 79 - 35= 44 neutrons

⇒Since it does have 35 protons, it is an isotope of Bromine. This isotope has 44 neutrons

⇒ This is 79Br, which is a stable isotope of Bromine.

3) A=79, N = 44

Z = A - N ⇒ Z = 79 - 44 = 35

Z = protons = electrons .So this element has 35 protons, as well as 35 electrons. It also has 44 neutrons.

⇒Since it does have 35 protons, it is an isotope of Bromine, with 44 neutrons: 79Br

4) Z = 44, N = 44

Z = protons = electrons .So this element has 44 protons, as well as 44 electrons.

A = 44 + 44 ⇒ A = 88

⇒Since it doesn't have 35 protons, it isn't an isotope of Bromine, but of Ruthenium (Ru) : 88Ru

⇔So the second and third option are isotopes of Bromine

6 0

3 years ago

Graphite from a pencil and a diamond ring are made of the same material. Explain how this is possible. Include a detailed descri

jekas [21]

Answer:

Explanation:

Both diamond and graphite are made entirely out of carbon.In a diamond, the carbon atoms are arranged tetrahedrally. Each carbon atom is attached to four other carbon with a C-C-C bond angle of 109.5 degrees. It is a strong, rigid three-dimensional structure that results in an infinite network of atoms. This accounts for diamond's hardness, extraordinary strength and durability and gives diamond a higher density than graphite. Because of its tetrahedral structure, diamond also shows a great resistance to compression. Diamond will scratch all other materials and is the hardest material known. It is the best conductor of heat that we know, conducting up to five times the amount that copper does. Diamond also conducts sound, but not electricity; it is an insulator, and its electrical resistance, optical transmissivity and chemical inertness are correspondingly remarkable.

The carbon atoms in graphite are also arranged in an infinite array, but they are layered. These atoms have two types of interactions with one another. In the first, each carbon atom is bonded to three other carbon atoms and arranged at the corners of a network of regular hexagons with a 120-degree C-C-C bond angle. These planar arrangements extend in two dimensions to form a horizontal, hexagonal "chicken-wire" array. In addition, these planar arrays are held together by weaker forces. The distance between two layers is longer than the distance between carbon atoms within each layer. This three-dimensional structure accounts for the physical properties of graphite. Unlike diamond, graphite can be used as a lubricant or in pencils because the layers cleave readily. It is soft and slippery, and its hardness is less than diamond . Graphite also has a lower density (2.266 grams per cubic centimeter) than diamond. The planar structure of graphite allows electrons to move easily within the planes. This permits graphite to conduct electricity and heat as well as absorb light and, unlike diamond, appear black in color.

8 0

3 years ago

The helium flash converts helium to the heavier element _____.