All categories

3 years ago

luminous objects such as flashlights emit light that we can see. how do we see an object that isnt luminous?

1 answer:

5 0

In order for us to see an object that is non-luminous, it must reflect some of the light it receives from a luminous source, such as the Sun. Most of the objects we see, such as cars, clouds or even the Moon, are not luminous; it is just that they reflect sunlight

You might be interested in

Ethanol (c2h5oh) melts at -114Â°c. the enthalpy of fusion is 5.02 kj/mol. the specific heats of solid and liquid ethanol are 0.9

maria [59]

You'll want to add three amounts of heat.

(1) Specific heat of lowering the temperature from -135°C to the melting point -114°C
(2) Latent heat of fusion/melting
(3) Specific heat of elevating the temperature from -114°C to -50°C

(1) E = mCΔT = (25 g)(0.97 J/g·°C)(1 kJ/1000 J)(-114 - -135) = 0.509 kJ
(2) E = mΔH = (25 g)(5.02 kJ/mol)(1 mol/46.07 g ethanol) = 2.724 kJ
(3) E = mCΔT = (25 g)(2.3 J/g·°C)(1 kJ/1000 J)(-50 - -114) = 3.68 kJ

Summing up all energies, the answer is 6.913 kJ.

7 0

3 years ago

Name the following compound: C5Si7

skad [1K]

Answer:

Pentacarbon heptasilicide.

Explanation:

In order to name the following compound, we need to identify whether it is molecular or ionic.

Molecular compounds consist of non-metal atoms, while ionic compounds would have metal cations in their composition.

In the given compound, $C_5Si_7$ , we have two non-metals, carbon and silicon, meaning we should follow the molecular compound naming rules. The rules involve using prefixes to state the number of individual atoms.

The two prefixes required here are 'penta' for 'five' to indicate 5 carbon atoms present and 'hepta' for 'seven' to indicate 7 silicon atoms present.

The first part of the name would be pentacarbon (notice that the standard name for the first element is used). The second part would be heptasilicide (notice that the second atom would have an ending of -ide followed by the standard beginning of silicon).

4 0

3 years ago

Classify each change as physical or chemical.

trasher [3.6K]

A chemical

B physical

C physical

D Chemical

4 0

3 years ago

Predict the following product(s) of the following reaction? F2 + KCI →

slega [8]

Answer:

${ \rm{F _{2(g)} + 2KCl _{(aq)} → { \bold{2KF _{(g)} + Cl_{2(g)} }}}}$

Explanation:

» The prediction is 98% correct because single displacement reaction type is highly possible.

This is because Fluorine has is more electronegative than Chlorine in Potassium Chloride. So, it strongly displaces Chlorine from the solution hence forming Chlorine gas.

» The 2% of wrong prediction maybe because of wrong reactant measurements following mole concept chemistry.

If you are asked the observation,

Observation » A green yellowish gas is formed.

This gas is Chlorine gas (Cl2)

5 0

2 years ago

What occurs when a magnesium atom becomes a magnesium ion?

IgorLugansk [536]

The atom then has more protons than electrons and so it will be positively charged, a positive ion. Example: A magnesium atom may lose two electrons and become a Mg2+ ion. Non-metal atoms may gain electrons and become negatively charged. ... (It loses two electrons.)

6 0

3 years ago