How many types of biodiversity Are there

D is a green crystalline solid that dissolves in water to give a very pale green solution addition of sodium hydroxide solution

Ksivusya [100]

Answer:

I think its iron(II) oxide

Explanation:

The substance is black but when it's mixed with water it turns green solution so when mixed with sodium Hydroxide it turns green

5 0

2 years ago

The hydrogen atom is not actually electronegative enough to form bonds to xenon. were the xenon-hydrogen bond to exist, what wou

Marat540 [252]

Answer : The structure of $XeH_4$ will be square-planar.

Explanation :

In the given molecule $XeH_4$ , 'Xe' is the central atom and 'H' is the terminal atom.

Xenon has 8 valence electrons and hydrogen has 1 valence electron. Therefore, the total number of valence electrons are 8 + 4(1) = 12 electrons.

The number of electrons used in Xe-H bonding = 8 electrons

The remaining electrons which are used as lone pair on central atom (Xe) = 12 - 8 = 4 electrons

There are 4 bonding pairs and 2 lone pairs of electrons, they will be arranged in the octahedral arrangement around the central atom with 2 lone pairs of electrons on central atom. The lone pairs are arranged linearly across the central atom. The resulting structure will be square-planar.

The structure of $XeH_4$ is shown below.

5 0

2 years ago

A student has four resistors. Each resistor has a resistance of 100 ohms.

ValentinkaMS [17]

Answer:

The minimum resistance is 25 ohms.

Explanation:

Resistance of each resistor is 100 ohms. When resistors are connected in parallel, the equivalent resistance is lowest. For parallel combination, the equivalent resistance is given by :

$\dfrac{1}{R}=\dfrac{1}{R_1}+\dfrac{1}{R_2}+....$

Here, all resistors are 100 ohms. So,

$\dfrac{1}{R}=\dfrac{1}{100}+\dfrac{1}{100}+\dfrac{1}{100}+\dfrac{1}{100}\\\\R=25\ \Omega$

So, the minimum resistance is 25 ohms.

7 0

2 years ago

How much heat is released as the temperature of 25.2 grams of iron is decreased from 72.1°C to 9.8°C? The specific heat of iron

prisoha [69]

Answer:

$Q=-697.06\ J$

Negative sign says that release of heat.

Explanation:

The expression for the calculation of the heat released or absorbed of a process is shown below as:-

$Q=m\times C\times \Delta T$

Where,

$\Delta H$ is the heat released or absorbed

m is the mass

C is the specific heat capacity

$\Delta T$ is the temperature change

Thus, given that:-

Mass = 25.2 g

Specific heat = 0.444 J/g°C

$\Delta T=9.8-72.1\ ^0C=-62.3\ ^0C$

So,

$Q=25.2\times 0.444\times -62.3\ J=-697.06\ J$

Negative sign says that release of heat.

8 0

2 years ago

What indicators of a chemical reaction occurred in the following equation?

ch4aika [34]

Answer:

1) evolution of gas

2) evolution of heat

Explanation:

In this reaction, glucose is broken down into its constituents; carbon dioxide and water. The question is to decipher indicators of a chemical reaction from the equation.

If we look at the equation carefully, we will notice that a gas was evolved (CO2). The evolution of a gas indicates that a chemical reaction must have taken place. Secondly, energy is given off as heat. This is another indication that a chemical reaction has taken place.

6 0

2 years ago