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4 years ago

Which element is classified as an alkali metal?

1 answer:

8 0

Answer: The alkali metals consist of the chemical elements lithium (Li), sodium (Na), potassium (K),[note 1] rubidium (Rb), caesium (Cs),[note 2] and francium (Fr).

Explanation:

You might be interested in

How many valence electrons do alkali metals have?

Lana71 [14]

1 valence electron in alkali metals.

3 0

3 years ago

Part 1: Name the type of chemical reaction that occurs when calcium hydroxide (Ca(OH)2) reacts with nitric acid (HNO3).

liberstina [14]

<u>Answer:</u>

<u>For 1:</u> Neutralization reaction

<u>For 2: </u>Zinc is more reactive than lead and less reactive than calcium.

<u>Explanation:</u>

<u>For (1):</u>

When a base reacts with an acid to form a salt and water molecule, it is known as a neutralization reaction. The general equation follows:

$HX+BOH\rightarrow BX+H_2O$

The chemical equation for the reaction of calcium hydroxide and nitric acid follows:

$Ca(OH)_2(aq)+2HNO_3(aq)\rightarrow Ca(NO_3)_2(aq)+2H_2O(l)$

<u>For (2):</u>

A single displacement reaction is defined as the reaction in which a more reactive metal displaces a less reactive metal from its salt solution. The general chemical equation follows:

$A+BX\rightarrow AX+B$

where,

Metal A is more reactive than metal B

The reactivity of metals is judged by the reactivity series where a metal lying above in the series is more reactive than the metal lying below it.

From the reactivity series below,

Zinc lies above in the series than lead thus is more reactive and will easily replace lead from its aqueous solution.

While zinc lies below in the series than calcium thus is less reactive and will not easily replace calcium from its aqueous solution.

$Zn(s)+Pb(NO_3)_2(aq)\rightarrow Zn(NO_3)_2(aq)+Pb(s)$

$Zn(s)+CaCl_2(aq)\rightarrow \text{No reaction}$

5 0

3 years ago

What are other portals of entry besides needlesticks?

aivan3 [116]

Answer:

Inhalation (via the respiratory tract)Absorption (via mucous membranes such as the eyes) Ingestion (via the gastrointestinal tract)

Explanation:

The opening where an infectious disease enters the host's body such as mucus membranes, open wounds, or tubes inserted in body cavities like urinary catheters or feeding tubes.

6 0

2 years ago

How many joules of heat are absorbed to raise the temperature of 435 grams of water at 1 atm from 25°C to its boiling point, 100

zepelin [54]

The energy absorbed may be calculated using:
Q = mcΔT
Where Q is the energy absorbed, m is the mass of water, c is the specific heat capacity of the water and ΔT is the change is the temperature of the water. Substituting the values,
Q = (435)(4.18)(100-25)
Q = 136,372 J

The energy absorbed is 136.4 kJ

7 0

3 years ago

The density of aluminium is 2830 Kg/M^3. what is the density of aluminum in g/cm^3?

postnew [5]

<h3>Answer:</h3>

2.83 g/cm³

<h3>Explanation:</h3>

Density of a substance is the ratio of mass of the substance to its volume.

Therefore;

Density is given by dividing mass of a substance by its volume.
It is measure in g/cubic centimeters or kg per cubic meters.

In this case;

Density of Al = 2830 Kg/m³

We are required to convert is to g/cm³

We use the relationship;

1 g/cm³ = 1000 kg/m³

Therefore;

= 2830 kg/m³ ÷ 1000 kg/m³

= 2.83 g/cm³

Hence, 2830 kg/m³ of Aluminium is equivalent to 2.83 g/cm³

4 0

4 years ago