1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
BaLLatris [955]
3 years ago
12

Define essential elements and how many elements are required for life

Chemistry
1 answer:
Travka [436]3 years ago
3 0
Living organisms contain relatively large amounts of oxygen, carbon, hydrogen, nitrogen, and sulfur (thesefive elements are known as the bulk elements), along with sodium, magnesium, potassium, calcium, chlorine, and phosphorus (these six elements are known as macrominerals).
You might be interested in
Why does the atmosphere have holes in it? A. Pollution B. Fuel from Cars/Machines
a_sh-v [17]

Answer:

the answer is d .

Explanation:

all of these have pollutants and chemicals in them , damaging the ozone with carbon dioxide .

7 0
3 years ago
What causes polar bonds
yulyashka [42]

Answer:

Bonds are polar when one element in a compound is more electronegative than the other. This creates a dipole in the molecule where one end of the molecule is partially positive and one end is partially negative

Explanation:

8 0
3 years ago
Write an 250 words about Water Purification and Filtration
kotykmax [81]

Answer:

Water purification is the process of removing undesirable chemicals, biological contaminants, suspended solids and gases from contaminated water. The goal is to produce water fit for a specific purpose. Most water is purified for human consumption (drinking water), but water purification may also be designed for a variety of other purposes, including meeting the requirements of medical, pharmacological, chemical and industrial applications. In general the methods used include physical processes such as filtration,sedimentation, and distillation, biological processes such as slow sand filters or biologically active carbon, chemical processes such asflocculation and chlorination and the use of electromagnetic radiation such as ultraviolet light.

Extreme lack or loss of water may lead to dehydration of the body and other health complications. For this reason, governments ensure that citizens have access to clean and safe water for domestic use. Clean water is essential in ensuring that no pathogens or impurities are ingested by people, either through direct drinking or through food.

To attain these standards of water, purification is important. Water purification involves physical and chemical processes, which are carried out stepwise to ensure the water is safe and free from any harm. This directional process essay synthesizes the steps, which have to be followed to achieve this task.

In essence, water purification denotes the process used to free water from impurities like bacteria and contaminants. Since the process is aimed at eliminating all the impurities present in the water, it is necessary to apply chemical and physical methods of separation in an orderly manner.

Explanation:

6 0
3 years ago
How many molecules are there in 560 grams of CoCl2?​
Marrrta [24]

Answer:

25.89  × 10²³ molecules

Explanation:

Given data:

Mass of CoCl₂ = 560 g

Number of molecules present = ?

Solution:

Number of moles of CoCl₂:

Number of moles = mass/molar mass

Number of moles = 560 g/ 129.84 g/mol

Number of moles = 4.3 mol

Avogadro number:

The given problem will solve by using Avogadro number.

It is the number of atoms , ions and molecules in one gram atom of element, one gram molecules of compound and one gram ions of a substance.  The number 6.022 × 10²³ is called Avogadro number.

1 mole = 6.022 × 10²³ molecules

4.3 mol ×  6.022 × 10²³ molecules /1 mol

25.89  × 10²³ molecules

5 0
3 years ago
Which of these has the most covalent character? <br> NaF Caf2 Bef2 CsF SrF2
Ksenya-84 [330]

Thus BeF2 is of most covalent character.

Anyways, covalent/ionic character is a bit tricky to figure out; we measure the difference in electronegativity of two elements bonding together and we use the following rule of thumb: if the charge is 0 (or a little more), the bond is non-polar covalent; if the charge is > 0 but < 2.0 (some references say 1.7), the bond is polar covalent; if the charge is > 2.0 then the bond is ionic. Covalent character refers to smaller electronegativity difference while ionic character refers to greater electronegativity difference.


Now, notice all of our bonds are with F, fluorine, which has the highest electronegativity of 3.98. This means that to determine character we need to consider the electronegativities of the other elements -- whichever has the greatest electronegativity has the least difference and most covalent character.
Na, sodium, has electronegativity of 0.93, so our difference is ~3 -- meaning our bond is ionic. Ca, calcium, has 1.00, leaving our difference to again be ~3 and therefore the bond is ionic. Be, beryllium, has 1.57 yielding a difference of ~2.5, meaning we're still dealing with ionic bond. Cs, cesium, has 0.79, meaning our difference is again ~3 and therefore again our compound is of ionic bond. Lastly, we have Sr, strontium, with an electronegativity of 0.95 and therefore again a difference of roughly 3 and an ionic bond. <span>
</span>
3 0
3 years ago
Other questions:
  • When aqueous solutions of K3PO4 and Ba(NO3)2 are combined, Ba3(PO4)2 precipitates. Calculate the mass, in grams, of the Ba3(PO4)
    5·1 answer
  • velocity and time information for a leftward moving car are shown. t = 4.0s v= 4.0 m/s. t = 0.0 v=20.0 m/s. what is the magnitud
    8·1 answer
  • If you have 0.56 moles of an ideal gas at 87c and a pressure of 569 torr, what volume will the gas take up
    7·1 answer
  • When is a salt formed?
    5·1 answer
  • Why does the atomic radius of elements get bigger as we go from top to bottom on the periodic table?
    10·2 answers
  • A sodium hydroxide solution is made by mixing 8.70 g NaOH with 100 g of water. The resulting solution has a density of 1.087 g/m
    8·1 answer
  • What does it mean if something is insoluble?
    8·1 answer
  • For the following reaction, 3.70 grams of oxygen gas are mixed with excess carbon monoxide . The reaction yields 8.25 grams of c
    15·1 answer
  • What is the density of an aqueous solution that is 50.0% KOH by mass and has a KOH concentration of 13.39 M?
    5·1 answer
  • wright it in 500 words Submit your persuasive essay about nuclear power. Remember to proofread your work before submitting.
    9·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!