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3 years ago

A _____ works by lighting the slide containing the specimen from below with a light bulb.

Chemistry

1 answer:

lesya692 [45]3 years ago

5 0

Condenser Lens - This lens system is located immediately under the stage and focuses the light on the specimen.

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*BRAINLEST* is a solution an element, compound, homogenous mixture, or heterogeneous mixture?

castortr0y [4]

Homogenous mixture

Brainliest?

8 0

3 years ago

Hydroxylamine is a weak molecular base with kb = 6.6 x 10-9. what is the ph of a 0.0500 m solution of hydroxylamine?

7nadin3 [17]

Answer is: pH of hydroxylamine solution is 9,23.

Kb(NH₂OH) = 1,8·10⁻⁵.
c₀(NH₂OH) = 0,0500 M = 0,05 mol/L.
c(NH₂⁺) = c(OH⁻) = x.

c(NH₂OH) = 0,05 mol/L - x.
Kb = c(NH₂⁺) · c(OH⁻) / c(NH₂OH).

0,0000000066 = x² / (0,05 mol/L - x).

solve quadratic equation: x = c(OH⁻) = 0,000018 mol/L.
pOH = -log(0,000018 mol/L) = 4,74.
pH = 14 - 4,74 = 9,23.

4 0

3 years ago

What’s the electron configuration of an N-3 ion

Alla [95]

Answer:

1s2 2s2 2p6

Explanation:

The nitride ion(N^3-) is formed when nitrogen gains three electrons. Nitrogen possesses seven electrons in its orbitals and ordinarily has the electronic configuration; 1s2 2s2 2p3. However,being in group 15, nitrogen can accept three electrons to form the nitride ion and complete its octet of electrons. When this happens, three electrons are added to the nitrogen atom and the electronic configuration is now the same as that of Neon, its closest noble gas which is 1s2 2s2 2p6. Hence the answer given above.

Elements can accept or donate electrons in order to complete their octet structure in accordance to the octet rule which states that atoms and ions must possess eight electrons in their outermost shell in order to attain chemical stability. The reason for ion formation and chemical reaction is in order for species to attain the octet structure.

8 0

3 years ago

What is the electronic configuration of the following atoms?

Nastasia [14]

Answer:The electron configuration of an atom shows the number of electrons in each sublevel in each energy level of the ground-state atom. To determine the electron configuration of a particular atom, start at the nucleus and add electrons one by one until the number of electrons equals the number of protons in the nucleus. Each added electron is assigned to the lowest-energy sublevel available. The first sublevel filled will be the 1s sublevel, then the 2s sublevel, the 2p sublevel, the 3s, 3p, 4s, 3d, and so on. This order is difficult to remember and often hard to determine from energy-level diagrams such as Figure 5.8

A more convenient way to remember the order is to use Figure 5.9. The principal energy levels are listed in columns, starting at the left with the 1s level. To use this figure, read along the diagonal lines in the direction of the arrow. The order is summarized under the diagram

7 0

3 years ago

Type the correct answer in the box. Express your answer to three significant figures. Calcium nitrate reacts with sodium phospha

RoseWind [281]

6.07 grams is the theoretical yield of calcium phosphate (Ca₃(PO₄)₂).

<h3>How we calculate mass from moles?</h3>

Mass of any substance can be calculated by using moles as:

n = W/M, where

W = required mass

M= molar mass

Given chemical reaction is:

3Ca(NO₃)₂ + 2Na₃PO₄ → 6NaNO₃ + Ca₃(PO₄)₂

From the stoichiometry it is clear that:

3 moles of Ca(NO₃)₂ = produce 1 mole of Ca₃(PO₄)₂

Given mass of Ca(NO₃)₂ = 96.1g

Mole of Ca(NO₃)₂ = 96.1g/164g/mol = 0.5859moles

So, 0.5859 moles of Ca(NO₃)₂ = produce 0.5859×1/3 = 0.0196 moles of Ca₃(PO₄)₂

Required mass of Ca₃(PO₄)₂ will be calculated by using moles as:

W = 0.0196mole × 310g/mole = 6.07 grams

Hence, 6.07 grams is the theoretical yield of calcium phosphate.

To know more about moles, visit the below link:

brainly.com/question/15373263

7 0

2 years ago