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liberstina [14]
3 years ago
12

Whatis the SI unit used by chemists to measure the amount of an element or substance

Chemistry
2 answers:
4vir4ik [10]3 years ago
5 0

Answer:

mole

Explanation:

just cause

Harman [31]3 years ago
3 0
The answer is Mole, but send me a message if you need the equation for how to get it
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CAN SOMEONE REWRITE/SHORTEN THIS FOR ME PLEASE? I'LL GIVE BRAINLIEST
Alex17521 [72]

Answer:

Here you go! 50% of your writing piece

Explanation:

Foods produced from or using GM organisms are often referred to as GM foods.

GM foods are developed and marketed because there is some advantage either to the producer or consumer of these GM foods. GM seed developers wanted their products to be accepted by producers and have concentrated on innovations that bring direct benefit to farmers and generally the food industry.

One objective for developing plants based on GM organisms is to improve crop protection. The GM crops currently on the market are mainly aimed at an increased level of crop protection through the introduction of resistance against plant diseases caused by insects or viruses or through increased tolerance towards herbicides.

Resistance against insects is achieved by incorporating into the food plant the gene for toxin production from the bacterium Bacillus thuringiensis. GM crops that inherently produce this toxin have been shown to require lower quantities of insecticides in specific situations, where pest pressure is high.

7 0
4 years ago
Radioactivity in our world _____.
sergij07 [2.7K]
Radioactivity in our world <span>b. is as old as the universe.
</span><span>Radioactive atom spontaneously emits energetic particles or waves, while decays on lighter nuclei (atoms with smaller atomic mass). Radioactivity is used to calculate how old is Earth and living things, for that purpose isotope of carbon is used.</span>
4 0
3 years ago
Please help
lisabon 2012 [21]

Answer:

There are 2 hydrogen atoms, one magnesium atom, and 5 atoms in total.

Explanation:

We are given a compound in formula form. To make things easier to understand, we can first convert this to the name of the compound.

  • When a compound contains one or more elements in parentheses, these are usually a <u>polyatomic ion</u>.
  • Polyatomic ions are ions made up of two or more elements with a positive or negative charge over the entire ion. Commons examples of these NH₄⁺ (ammonia) and HCO₃⁻ (bicarbonate).
  • You can combine metals with polyatomic ions to create commonly known compounds, such as baking soda. The chemical name for baking soda is sodium bicarbonate, so we can combine Na (sodium) with HCO₃⁻ (bicarbonate) and create sodium bicarbonate: NaHCO₃.

This compound is one magnesium atom bonded to two hydroxide ions.

  • Hydroxide is the compound between one hydrogen atom and one oxygen atom. The compound overall adopts a negative charge of 1.
  • If we have one hydrogen atom and one oxygen atom, the most electronegative atom is written first in chemical formulas. Therefore, the symbol for Oxygen (O) goes first.
  • Then, write in the hydrogen atom directly after the O symbol: OH.
  • Finally, since we have a negative charge on the ion, we need to play a negative sign as a superscript for the compound. Therefore, this becomes OH⁻.

Now, we need to determine the charge on the Magnesium atom which is determined from the amount of valence electrons the atom has.

  • On a periodic table, the symbol for Magnesium is Mg and this element has 2 valence electrons.
  • In order to fulfill the Octet Rule, the It is more likely to give up 2 electrons to a nonmetal than it is to gain 6, so we can safely assume that the charge is ²⁺.
  • We need to use the criss-cross technique to transfer the charges between the element and the ion, so the negative 1 charge goes to the Mg, which does not appear (negative 1 or positive 1 are implied) and since the magnesium has a charge of positive 2, this is the subscript for the hydroxide ion.
  • Therefore, our compound becomes Mg(OH)₂, and we have labeled this as magnesium hydroxide.

Now, to the number of atoms:

  • The new charge on Mg is 1-, so there is only one atom of Mg.
  • The charge is 2+ on the OH ion, so there are two atoms of H and two atoms of O.
  • Two atoms of oxygen, two atoms of hydrogen, and one atom of magnesium add up to be five atoms in total.
3 0
3 years ago
I know there are 4.5*10^-9 seconds in 4.5 nanoseconds, but when I enter it into my TI-30xIIs, I get 4.5*10^-10. I enter it as 4.
o-na [289]

Answer:

You are not using properly the function exponential in your calculator

Explanation:

When a number is too big or too small we use scientific notation. This is a number between 1 a 10 multiplied by a power of 10.

When you are writing 4.5*10^-9 you are actually writing 0.0000000045 in scientific notation.

When you enter this in the calculator you have to use the function EXP after the first two numbers.

Steps:    1) Enter 4.5

             2) Enter EXP

             3) Enter minus (-)

             4) Enter 9

8 0
4 years ago
An electron is a particle with a _____.
astra-53 [7]
The Answer is B.

*NEGATIVE CHARGE, FOUND OUTSIDE THE NUCLEUS*
5 0
3 years ago
Read 2 more answers
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