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3 years ago

About how many times longer than modern humans have hooved mammals lived on earth?

Chemistry

1 answer:

abruzzese [7]3 years ago

8 0

Answer:

I think it should be about maybe the times of the dinosaurs

also I think 23 to 16 billion years

Explanation:

No explanation sorry if im wrong

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Wat two common uses for Gallium??

Ann [662]

Answer:

mirrors and metal thermometers

Explanation:

ooga booga

6 0

3 years ago

Read 2 more answers

Can someone help me fill out the chart and explain what i should do, please?

Alina [70]

To determine the electronegativity for each bond you need to calculate the difference of electronegativity of the atoms forming the bond.

If the difference is equal or greater than 1.7 you have an ionic bond.

If the difference is between 0.4 and 1.6 you have a polar covalent bond.

If the difference is between 0 and less than 0.4 you have a nonpolar covalent bond.

1) In NH₃ there is a nitrogen - hydrogen bond.

electronegativity of nitrogen - electronegativity of hydrogen =

3 - 2.2 = 0.8 → polar covalent bond

2) In N₂ there is a nitrogen-nitrogen bond.

electronegativity of nitrogen - electronegativity of nitrogen =

3 - 3 = 0 → nonpolar covalent bond

3) In H₂O there is an oxygen - hydrogen bond.

electronegativity of oxygen - electronegativity of hydrogen =

3.5 - 2.2 = 1.3 → polar covalent bond

4) In PCl₃ there is a chlorine - phosphorus bond.

electronegativity of chlorine - electronegativity of phosphorus = 3 - 2.1 = 0.9 → polar covalent bond

4) In HBr there is a bromine - hydrogen bond.

electronegativity of bromine - electronegativity of hydrogen = 2.8 - 2.2 = 0.6 → polar covalent bond

5) In MgCl₂ there is a chlorine - magnesium bond.

electronegativity of chlorine - electronegativity of magnesium = 3 - 1.2 = 1.8 → ionic bond

6) In F₂ there is a fluorine - fluorine bond.

electronegativity of fluorine - electronegativity of fluorine =

4 - 4 = 0 → nonpolar covalent bond

7) In CO₂ there is an oxygen - carbon bond.

electronegativity of oxygen- electronegativity of carbon =

3.5 - 2.5 = 1 → polar covalent bond

8) In LiCl there is a chlorine - lithium bond.

electronegativity of chlorine - electronegativity of lithium =

3 - 1 = 2 → ionic bond

9) In Na₂O there is an oxygen - sodium bond.

electronegativity of oxygen - electronegativity of sodium =

3.5 - 0.9 = 2.6 → ionic bond

10) In CCl₄ there is a chlorine - carbon bond.

electronegativity of chlorine - electronegativity of carbon =

3 - 2.5 = 0.5 → polar covalent bond

5 0

3 years ago

C10H22 + O2 -- CO2 + H2O balance

Tasya [4]

Answer:

1,31÷2 =10,11

Explanation:

c10h22+31÷2o2=10co2+11h2o

5 0

3 years ago

A glass column is filled with mercury and inverted in a pool of mercury. The mercury column stabilizes at a height of 729 mm abo

harkovskaia [24]

The atmospheric pressure will be:

The pressure of the atmosphere resulting from the mercury column is 0.959 atm

What is atmospheric pressure?

The force that an object experiences from the weight of the air above it per unit area are known as atmospheric pressure.

Given: Height of mercury column = 729 mm Hg

To find: The pressure of the atmosphere

Calculation:

The atmospheric column resulting from the mercury column is calculated as follows:

1 atm =760 mm Hg

So, we can convert the 729 mm Hg to atm, and we get

Atmospheric pressure = 729 x 1 atm / 760 = 0.959 atm

Learn more about atmospheric pressure here,

brainly.com/question/14315894

#SPJ4

5 0

1 year ago

Using the solubility graph place the substances in order from most soluble (#1) to least soluble at 40°C. KNO3, NaClO3,KBr, NaCl

mestny [16]

Answer:

NaClO₃ > KBr > KNO₃ > NaCl.

Explanation:

The attached file contains the graph with the solubility curves for the four substances, KNO₃, NaClO₃, KBr, NaCl.

To determine the solubility of each salt at a certain temperature, you read the temperature on the horizontal axis, labeled Temperature (ºC), and move upward up to intersecting the curve of the corresponding salt. Then, move horizontally up to insersceting the vertical axis, labeled Solubility (g/100g of H₂O), to read the solubility.

The higher the reading on the vertical axis, the higher the solubility.

The red vertical line that I added is at a temperature of 40ºC.

The number in blue indicate the order in which the solubility curves are intersected at that temperature:

4: NaCl: this is the lowest solubility
3: KNO₃: this is the second lowest solubility
2: KBr: this is the third lowest solubility
1: NaClO₃: this is the highest solubility.

Thus, the rank, from most soluble to least soluble is:

NaClO₃ > KBr > KNO₃ > NaCl.

7 0

3 years ago