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3 years ago

Explain some of the benefits and problem associated with the pesticide DDT.

Chemistry

1 answer:

Dafna1 [17]3 years ago

4 0

Some benefits are that DDT helps us grow crops and keeps pests off our crops.

But DDT is harmful to the environment. If it gets into the water ways then if can harm fish and animals that eat the fish such as birds.

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Explain in your own words how electromagnetism works.

lesya692 [45]

Magnetic fields are created due to high levels of electricity

4 0

3 years ago

2. Determine the molarity of the NaOH solution in each trial. a. Trial 1 Molarity: b. Trial 2 Molarity: 3. Calculate the average

butalik [34]

Answer:

This question is incomplete

Explanation:

This question is incomplete but...

1) You can calculate the molarity of the NaOH for each trial by following the steps below.

The formula for Molarity (M) is

M = number of moles (n) ÷ volume (V)

where the unit of volume must be in Litres or dm³

The unit of molarity is mol/dm³ or mol/L or molar conc (M)

The final answer must have the unit of molarity

If the number of moles is not provided, look out for the mass of NaOH used and then calculate your number of moles (n) as

n = mass of NaOH used ÷ molar mass of NaOH

Where the atomic mass of sodium (Na) is 23, oxygen (O) is 16 and hydrogen (H) is 1. Hence, molar mass for NaOH is 23 + 16 + 1 = 40 g/mol

n = mass of NaOH used ÷ 40

2) Average Molarity will be (Trial 1 Molarity +Trial 2 Molarity) ÷ 2

Answer must be in mol/dm³ or mol/L or M

3) Label the volumentric flask containing the NaOH solution with the answer gotten from (2) above

3 0

3 years ago

Tate the law of conservation of mass. Then apply the law to this question: What would be the total

Savatey [412]

<span>The law of conservation of mass states that, "Mass can neither be created nor destroyed, only its form changes with respect to different forms of energy." In any reaction, say 10 gms of water is decomposed into its constituents Hydrogen and Oxygen. But the mass remains conserved for the reaction. Although mass and energy are inter-convertible. But,the net mass/energy remains conserved i.e. the mass of products will be equal to the mass of reactants. </span>

5 0

3 years ago

Perform the following calculations. Express the answers with the correct number of significant figures.

11Alexandr11 [23.1K]

Since there are no conversions to be done just add them as is
a) 1 g
b) 1.0 kg
c) 22 L
d) 3.6 cm
<span>e) 104.9 g</span>

7 0

3 years ago

An element's most stable ion forms an ionic compound with bromine, having the formula XBr. If the ion of element X has a mass nu

earnstyle [38]

Answer:

The element is Rubidium . The ion only loss one electron to make the electron 36 . But the proton number(atomic number) is 37. The chemical compound should RbBr

X = Rubidium(Rb)

Explanation:

The ion of element X has a mass number of 85 and electron of 36. An elements is charge if it either loss or receive electron. Base on the charge the ion has loss electron. Bromine usually possess a negatively charge ion. That makes the X electron a positively charge ion.

proton number = Atomic number

Proton number = electron number when not charged

Mass number = proton number + neutron number

Proton is usually same number with the electron to make the element neutral. But when the atom is charge the atom usually loss or gain electron.

In this case, the atom X loss one electron thereby reducing the electron number to 36 . Recall, the electron is equal to proton only if the atom is uncharged. This means the proton number should be 37 as one electron was loss.

Element with proton number(atomic number) of 37 is rubidium. It is an alkali metal that is very reactive.

8 0

4 years ago